{"id":838,"date":"2026-10-04T17:39:10","date_gmt":"2026-10-04T17:39:10","guid":{"rendered":"https:\/\/academic.pargaidefenceacademy.in\/Class-9th\/?p=838"},"modified":"2026-10-07T12:09:46","modified_gmt":"2026-10-07T12:09:46","slug":"chapter-7-work-energy-and-simple-machines","status":"publish","type":"post","link":"https:\/\/academic.pargaidefenceacademy.in\/Class-9th\/2026\/10\/04\/chapter-7-work-energy-and-simple-machines\/","title":{"rendered":"*Chapter 7* | Work, Energy and Simple Machines | \u0915\u093e\u0930\u094d\u092f, \u090a\u0930\u094d\u091c\u093e \u0914\u0930 \u0938\u0930\u0932 \u092e\u0936\u0940\u0928\u0947\u0902"},"content":{"rendered":"<div id=\"pl-838\"  class=\"panel-layout\" ><div id=\"pg-838-0\"  class=\"panel-grid panel-no-style\" ><div id=\"pgc-838-0-0\"  class=\"panel-grid-cell\" ><div id=\"panel-838-0-0-0\" class=\"widget_text so-panel widget widget_custom_html panel-first-child panel-last-child\" data-index=\"0\" ><div class=\"textwidget custom-html-widget\"><div id=\"CH7-INTRO-HI\" style=\"max-width:860px;margin:12px auto;border:4px solid #bf360c;border-radius:14px;background:#fbe9e7;font-family:'Noto Sans Devanagari',Arial,sans-serif;overflow:hidden;\">\n<div style=\"background:#bf360c;padding:10px;text-align:center;\"><span style=\"background:#fff;color:#bf360c;padding:7px 20px;border-radius:20px;font-weight:bold;font-size:14px;\">\u0905\u0927\u094d\u092f\u093e\u092f 7 - \u0915\u093e\u0930\u094d\u092f, \u090a\u0930\u094d\u091c\u093e \u0914\u0930 \u0938\u0930\u0932 \u092e\u0936\u0940\u0928\u0947\u0902 - \u0938\u093e\u092e\u093e\u0928\u094d\u092f \u092a\u0930\u093f\u091a\u092f<\/span><\/div>\n\n<div style=\"padding:10px 12px;\">\n<div id=\"c7h-1\" style=\"display:block;\"><div style=\"background:#b71c1c;color:#fff;padding:6px 14px;border-radius:20px;font-size:13px;font-weight:bold;display:inline-block;margin-bottom:8px;\">\ud83d\udd34 \u092d\u093e\u0917 1\/5 - \u092a\u093e\u0920 \u0915\u094d\u092f\u094b\u0902 \u092a\u0922\u093c\u093e\u092f\u093e \u091c\u093e\u0924\u093e \u0939\u0948?<\/div><div style=\"background:#fff;border:1.5px solid #bf360c;border-radius:10px;padding:12px;font-size:14px;line-height:1.9;height:580px;overflow-y:auto;\">\n\n<div style=\"background:#ffebee;border-left:4px solid #b71c1c;padding:8px 10px;font-weight:bold;\">\u0938\u094b\u091a\u094b \u0924\u094b - \u092a\u0947\u091c 116 \u091a\u093f\u0924\u094d\u0930 7.1 - \u092c\u091a\u094d\u091a\u094b\u0902 \u0915\u0940 \u092b\u093f\u0938\u0932\u0928 \u092a\u091f\u094d\u091f\u0940<\/div>\n- \u0928\u0940\u0932\u0940 \u0938\u094d\u0932\u093e\u0907\u0921 \u0915\u0947 \u0928\u0940\u091a\u0947 \u092c\u091a\u094d\u091a\u0947 \u0915\u093e \u0935\u0947\u0917 \u0915\u093f\u0924\u0928\u093e \u0939\u094b\u0917\u093e?<br>\n- \u0915\u094d\u092f\u093e \u0905\u0932\u0917-\u0905\u0932\u0917 \u0935\u091c\u0928 \u0915\u0947 \u0926\u094b \u092c\u091a\u094d\u091a\u0947 \u090f\u0915 \u0939\u0940 \u0938\u094d\u0932\u093e\u0907\u0921 \u0938\u0947 \u0928\u0940\u091a\u0947 \u0938\u092e\u093e\u0928 \u0935\u0947\u0917 \u0938\u0947 \u092a\u0939\u0941\u0901\u091a\u0947\u0902\u0917\u0947?<br>\n- \u0915\u093f\u0938 \u0938\u094d\u0932\u093e\u0907\u0921 \u0938\u0947 \u0928\u0940\u091a\u0947 \u0938\u092c\u0938\u0947 \u091c\u094d\u092f\u093e\u0926\u093e \u0935\u0947\u0917 \u092e\u093f\u0932\u0947\u0917\u093e?<br><br>\n\n<b>\u092a\u093e\u0920 \u0915\u093e \u092e\u0939\u0924\u094d\u0935 - \u0915\u094d\u092f\u094b\u0902 \u092a\u0922\u093c\u093e\u092f\u093e \u091c\u093e\u0924\u093e \u0939\u0948?<\/b><br>\n\u092a\u093f\u091b\u0932\u0947 \u0905\u0927\u094d\u092f\u093e\u092f 4 \u0914\u0930 6 \u092e\u0947\u0902 \u0906\u092a\u0928\u0947 \u0938\u0940\u0916\u093e \u0915\u093f \u092c\u0932 \u0915\u0948\u0938\u0947 \u0917\u0924\u093f \u092c\u0926\u0932\u0924\u0947 \u0939\u0948\u0902 \u0914\u0930 \u0917\u0924\u093f \u0915\u0947 \u0938\u092e\u0940\u0915\u0930\u0923 \u0914\u0930 \u0928\u094d\u092f\u0942\u091f\u0928 \u0915\u0947 \u0928\u093f\u092f\u092e\u094b\u0902 \u0938\u0947 \u0935\u093f\u0936\u094d\u0932\u0947\u0937\u0923 \u0915\u093f\u092f\u093e\u0964 \u0932\u0947\u0915\u093f\u0928 \u091c\u092c \u092c\u0932 \u0938\u092e\u092f \u0915\u0947 \u0938\u093e\u0925 \u092c\u0926\u0932\u0924\u0947 \u0939\u0948\u0902 \u092f\u093e \u091c\u091f\u093f\u0932 \u0924\u0930\u0940\u0915\u0947 \u0938\u0947 \u0915\u093e\u092e \u0915\u0930\u0924\u0947 \u0939\u0948\u0902 \u0924\u094b \u0938\u0940\u0927\u0947 \u0928\u093f\u092f\u092e \u0932\u0917\u093e\u0928\u093e \u092e\u0941\u0936\u094d\u0915\u093f\u0932 \u0939\u094b \u091c\u093e\u0924\u093e \u0939\u0948\u0964 \u0915\u094d\u092f\u093e \u0915\u094b\u0908 \u0906\u0938\u093e\u0928 \u0914\u0930 \u0924\u093e\u0915\u0924\u0935\u0930 \u0924\u0930\u0940\u0915\u093e \u0939\u0948 \u0910\u0938\u0940 \u0938\u094d\u0925\u093f\u0924\u093f\u092f\u094b\u0902 \u0915\u094b \u0938\u092e\u091d\u0928\u0947 \u0915\u093e?<br>\n\u0907\u0938 \u0905\u0927\u094d\u092f\u093e\u092f \u092e\u0947\u0902 \u0906\u092a \u0915\u093e\u0930\u094d\u092f, \u090a\u0930\u094d\u091c\u093e \u0914\u0930 \u0936\u0915\u094d\u0924\u093f \u0915\u0947 \u092c\u093e\u0930\u0947 \u092e\u0947\u0902 \u092a\u0922\u093c\u0947\u0902\u0917\u0947 \u091c\u093f\u0938\u0938\u0947 \u0917\u0924\u093f \u0914\u0930 \u0906\u092a\u0938\u0940 \u0915\u094d\u0930\u093f\u092f\u093e \u0915\u093e \u0935\u093f\u0936\u094d\u0932\u0947\u0937\u0923 \u0906\u0938\u093e\u0928 \u0939\u094b \u091c\u093e\u0924\u093e \u0939\u0948\u0964 \u0906\u092a \u0938\u0930\u0932 \u092e\u0936\u0940\u0928\u094b\u0902 \u0915\u0947 \u092c\u093e\u0930\u0947 \u092e\u0947\u0902 \u092d\u0940 \u0938\u0940\u0916\u0947\u0902\u0917\u0947 \u091c\u094b \u0915\u092e \u092e\u0947\u0939\u0928\u0924 \u092e\u0947\u0902 \u091c\u094d\u092f\u093e\u0926\u093e \u0915\u093e\u092e \u0915\u0930\u0928\u0947 \u092e\u0947\u0902 \u092e\u0926\u0926 \u0915\u0930\u0924\u0940 \u0939\u0948\u0902\u0964 \u092f\u0947 \u0930\u094b\u091c\u092e\u0930\u094d\u0930\u093e \u0915\u0940 \u0915\u0908 \u092e\u0936\u0940\u0928\u094b\u0902 \u0915\u0940 \u092c\u0941\u0928\u093f\u092f\u093e\u0926 \u0939\u0948\u0902\u0964 \u090a\u0930\u094d\u091c\u093e \u091c\u094b \u0915\u093e\u0930\u094d\u092f \u0915\u0930\u0928\u0947 \u0915\u0940 \u0915\u094d\u0937\u092e\u0924\u093e \u0939\u0948, \u0939\u0930 \u0930\u094b\u091c \u0915\u0947 \u0915\u093e\u092e \u0915\u0947 \u092a\u0940\u091b\u0947 \u0939\u0948 \u091a\u093f\u0924\u094d\u0930 7.1\u0964<br><br>\n\n<b>\u091a\u093f\u0924\u094d\u0930 7.1: \u0915\u093e\u0930\u094d\u092f \u0915\u0930\u0928\u0947 \u0915\u0947 \u0932\u093f\u090f \u090a\u0930\u094d\u091c\u093e \u0905\u0932\u0917-\u0905\u0932\u0917 \u0938\u094d\u0930\u094b\u0924\u094b\u0902 \u0938\u0947 \u0906\u0924\u0940 \u0939\u0948:<\/b><br>\n- \u092d\u094b\u091c\u0928 \u0938\u0947 \u091a\u0932\u0928\u0947 \u0915\u0940 \u090a\u0930\u094d\u091c\u093e \u092e\u093f\u0932\u0924\u0940 \u0939\u0948<br>\n- \u092c\u093f\u091c\u0932\u0940 \u0938\u0947 \u092a\u0902\u0916\u093e \u0918\u0942\u092e\u0928\u0947 \u0915\u0940 \u090a\u0930\u094d\u091c\u093e<br>\n- \u0908\u0902\u0927\u0928 \u0938\u0947 \u0917\u093e\u0921\u093c\u0940 \u091a\u0932\u0928\u0947 \u0915\u0940 \u090a\u0930\u094d\u091c\u093e<br><br>\n\n\u0939\u092e \u0930\u094b\u091c\u092e\u0930\u094d\u0930\u093e \u092e\u0947\u0902 \u0915\u093e\u0930\u094d\u092f, \u090a\u0930\u094d\u091c\u093e, \u0936\u0915\u094d\u0924\u093f \u0936\u092c\u094d\u0926 \u092c\u094b\u0932\u0924\u0947 \u0939\u0948\u0902\u0964 \u091c\u0948\u0938\u0947 \u0905\u0927\u094d\u092f\u093e\u092f 1 \u092e\u0947\u0902 \u0938\u0940\u0916\u093e, \u0935\u093f\u091c\u094d\u091e\u093e\u0928 \u092e\u0947\u0902 \u0907\u0928\u0915\u093e \u0938\u091f\u0940\u0915 \u092e\u0924\u0932\u092c \u0939\u0948\u0964 \u092a\u0939\u0932\u0947 \u0915\u093e\u0930\u094d\u092f \u0915\u094b \u092a\u0930\u093f\u092d\u093e\u0937\u093f\u0924 \u0915\u0930\u0924\u0947 \u0939\u0948\u0902\u0964<br><br>\n\n<b>\u0905\u0917\u094d\u0928\u093f\u0935\u0940\u0930 \u0915\u0947 \u0932\u093f\u090f \u092e\u0939\u0924\u094d\u0935:<\/b><br>\n- \u092b\u094c\u091c \u092e\u0947\u0902 \u092d\u093e\u0930\u0940 \u0938\u093e\u092e\u093e\u0928 \u0909\u0920\u093e\u0928\u093e, \u0918\u093f\u0930\u0928\u0940, \u0915\u094d\u0930\u0947\u0928, \u0922\u0932\u093e\u0928, \u0932\u0940\u0935\u0930 \u0938\u0947 \u0915\u093e\u092e \u0906\u0938\u093e\u0928 - \u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 \u0932\u093e\u092d<br>\n- \u091c\u0947\u091f \u0935\u093f\u092e\u093e\u0928 15000 kg \u0932\u0948\u0902\u0921\u093f\u0902\u0917 \u0921\u0947\u0915 \u0909\u0926\u093e\u0939\u0930\u0923 7.6 - 367500 N \u092c\u0932 100 m \u092e\u0947\u0902 \u0930\u094b\u0915\u0928\u093e - \u0917\u0924\u093f\u091c \u090a\u0930\u094d\u091c\u093e \u0915\u093e\u0930\u094d\u092f-\u090a\u0930\u094d\u091c\u093e \u092a\u094d\u0930\u092e\u0947\u092f<br>\n- \u090f\u0938\u094d\u0915\u0947\u092a \u0930\u0948\u0902\u092a \u091a\u093f\u0924\u094d\u0930 7.21 - 10000 kg \u091f\u094d\u0930\u0915 72 km\/h 20 m\/s \u092c\u094d\u0930\u0947\u0915 \u092b\u0947\u0932 30\u00b0 \u0922\u0932\u093e\u0928 \u0930\u0947\u0924 50000 N - \u0915\u093f\u0924\u0928\u0940 \u0932\u0902\u092c\u0940 \u0930\u0948\u0902\u092a \u091a\u093e\u0939\u093f\u090f - \u090a\u0930\u094d\u091c\u093e \u0938\u0902\u0930\u0915\u094d\u0937\u0923<br>\n- \u092a\u0928\u091a\u0915\u094d\u0915\u0940 \u0918\u0930\u093e\u091f \u091a\u093f\u0924\u094d\u0930 7.36 \u0939\u093f\u092e\u093e\u0932\u092f \u092e\u0947\u0902 \u0938\u094d\u0925\u093f\u0924\u093f\u091c \u2192 \u0917\u0924\u093f\u091c \u2192 \u092a\u0940\u0938\u0928\u093e - \u092c\u093e\u0901\u0927 \u092e\u0947\u0902 \u092c\u093f\u091c\u0932\u0940<br>\n- \u092c\u091a\u094d\u091a\u094b\u0902 \u0915\u094b \u0938\u092e\u091d\u0928\u093e - \u0905\u0932\u0917 \u0935\u091c\u0928 \u0915\u0947 \u092c\u091a\u094d\u091a\u0947 same \u0938\u094d\u0932\u093e\u0907\u0921 \u0938\u0947 same \u0935\u0947\u0917 \u0915\u094d\u092f\u094b\u0902? - v=\u221a(2gh) \u0935\u091c\u0928 \u092a\u0930 \u0928\u0939\u0940\u0902 \u0915\u0947\u0935\u0932 \u090a\u0901\u091a\u093e\u0908 \u092a\u0930 \u0928\u093f\u0930\u094d\u092d\u0930\u0964<br>\n\n<\/div><\/div>\n\n<div id=\"c7h-2\" style=\"display:none;\"><div style=\"background:#1565c0;color:#fff;padding:6px 14px;border-radius:20px;font-size:13px;font-weight:bold;display:inline-block;margin-bottom:8px;\">\ud83d\udd35 \u092d\u093e\u0917 2\/5 - \u0915\u093e\u0930\u094d\u092f \u0915\u0940 \u092a\u0930\u093f\u092d\u093e\u0937\u093e<\/div><div style=\"background:#fff;border:1.5px solid #bf360c;border-radius:10px;padding:12px;font-size:14px;line-height:1.9;height:580px;overflow-y:auto;\">\n\n<b>7.1 \u0915\u093e\u0930\u094d\u092f - \u092a\u0930\u093f\u092d\u093e\u0937\u093e - \u092a\u0947\u091c 118-119 \u091a\u093f\u0924\u094d\u0930 7.4-7.7:<\/b><br>\n\u091c\u092c \u092c\u0932 \u0932\u0917\u093e\u092f\u093e \u091c\u093e\u0924\u093e \u0939\u0948 \u0914\u0930 \u0935\u0938\u094d\u0924\u0941 \u092c\u0932 \u0915\u0940 \u0926\u093f\u0936\u093e \u092e\u0947\u0902 \u0939\u091f\u0924\u0940 \u0939\u0948 \u0924\u094b \u0915\u093e\u0930\u094d\u092f \u0939\u094b\u0924\u093e \u0939\u0948\u0964<br>\n<b>\u0938\u0942\u0924\u094d\u0930: W = F \u00d7 s - \u0938\u092e\u0940\u0915\u0930\u0923 7.2 - \u092c\u0932 \u00d7 \u092c\u0932 \u0915\u0940 \u0926\u093f\u0936\u093e \u092e\u0947\u0902 \u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928<\/b><br>\nSI \u092e\u093e\u0924\u094d\u0930\u0915 - \u091c\u0942\u0932 J - 1 J = 1 N \u00d7 1 m - 1 N = 1 kg m\/s\u00b2 \u0907\u0938\u0932\u093f\u090f 1 J = 1 kg m\u00b2\/s\u00b2<br>\n\u0917\u094d\u0930\u093e\u092b \u091a\u093f\u0924\u094d\u0930 7.4 \u092c\u0932-\u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928 \u0917\u094d\u0930\u093e\u092b \u092e\u0947\u0902 \u0915\u093e\u0930\u094d\u092f = \u091b\u093e\u092f\u093e\u0902\u0915\u093f\u0924 \u0906\u092f\u0924 \u0915\u093e \u0915\u094d\u0937\u0947\u0924\u094d\u0930\u092b\u0932 = 10 N \u00d71 m =10 J - \u092c\u0932 \u092c\u0926\u0932\u0924\u093e \u0939\u094b \u0924\u094b \u0917\u094d\u0930\u093e\u092b \u0915\u0947 \u0928\u0940\u091a\u0947 \u0915\u093e \u0915\u094d\u0937\u0947\u0924\u094d\u0930\u092b\u0932 \u092a\u094d\u0930\u093e\u0930\u0902\u092d\u093f\u0915 \u0905\u0902\u0924\u093f\u092e \u0938\u094d\u0925\u093f\u0924\u093f \u0915\u0947 \u092c\u0940\u091a\u0964<br><br>\n\n<b>7.1.1 \u0915\u093e\u0930\u094d\u092f \u0936\u0942\u0928\u094d\u092f \u0915\u092c? - \u092a\u0947\u091c 119:<\/b><br>\n- F=0 \u0924\u094b W=0<br>\n- s=0 \u0924\u094b W=0 \u091a\u093e\u0939\u0947 \u092c\u0932 \u0932\u0917\u093e\u0913 - \u0926\u0940\u0935\u093e\u0930 \u091a\u093f\u0924\u094d\u0930 7.5 \u0927\u0915\u0947\u0932\u0928\u0947 \u092a\u0930 \u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928 \u0928\u0939\u0940\u0902 \u0907\u0938\u0932\u093f\u090f \u0935\u0948\u091c\u094d\u091e\u093e\u0928\u093f\u0915 \u0905\u0930\u094d\u0925 \u092e\u0947\u0902 \u0915\u093e\u0930\u094d\u092f \u0928\u0939\u0940\u0902 - \u092e\u093e\u0901\u0938\u092a\u0947\u0936\u093f\u092f\u093e\u0901 \u092c\u093e\u0930-\u092c\u093e\u0930 \u092b\u0948\u0932\u0924\u0940 \u0938\u093f\u0915\u0941\u0921\u093c\u0924\u0940 \u0905\u0902\u0926\u0930\u0942\u0928\u0940 \u090a\u0930\u094d\u091c\u093e \u0916\u0930\u094d\u091a \u0925\u0915\u093e\u0928 \u0932\u0917\u0924\u0940 \u0932\u0947\u0915\u093f\u0928 \u0935\u0938\u094d\u0924\u0941 \u092a\u0930 \u0915\u093e\u0930\u094d\u092f \u0928\u0939\u0940\u0902\u0964<br>\n- \u092c\u0932 \u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928 \u0915\u0947 \u0932\u0902\u092c\u0935\u0924 \u0924\u094b W=0 \u091a\u093f\u0924\u094d\u0930 7.6 - \u0932\u0921\u093c\u0915\u0940 \u092c\u0915\u094d\u0938\u093e \u0932\u0947\u0915\u0930 \u091a\u0932\u0924\u0940 \u090a\u092a\u0930 \u0915\u0940 \u0913\u0930 \u092c\u0932 \u0935\u091c\u0928 \u0938\u0902\u0924\u0941\u0932\u0928 \u0915\u094d\u0937\u0948\u0924\u093f\u091c \u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928 - \u092c\u0932 \u0914\u0930 \u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928 \u0932\u0902\u092c\u0935\u0924 \u0907\u0938\u0932\u093f\u090f \u0915\u093e\u0930\u094d\u092f \u0936\u0942\u0928\u094d\u092f\u0964 \u090a\u0901\u091a\u0940 \u0915\u0915\u094d\u0937\u093e \u092e\u0947\u0902 \u0915\u094b\u0923 \u092a\u0930 \u0915\u093e\u0930\u094d\u092f \u092a\u0922\u093c\u094b\u0917\u0947\u0964<br><br>\n\n<b>7.1.2 \u0927\u0928\u093e\u0924\u094d\u092e\u0915 \u0914\u0930 \u090b\u0923\u093e\u0924\u094d\u092e\u0915 \u0915\u093e\u0930\u094d\u092f - \u091a\u093f\u0924\u094d\u0930 7.7:<\/b><br>\n\u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928 \u092c\u0932 \u0915\u0940 \u0926\u093f\u0936\u093e \u092e\u0947\u0902 same \u0924\u094b \u0927\u0928\u093e\u0924\u094d\u092e\u0915 - \u0935\u094d\u0939\u0940\u0932\u091a\u0947\u092f\u0930 \u0927\u0915\u0947\u0932\u0928\u093e \u091a\u093f\u0924\u094d\u0930 7.7a \u092c\u0932 \u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928 same \u0926\u093f\u0936\u093e \u0927\u0928\u093e\u0924\u094d\u092e\u0915 \u0915\u093e\u0930\u094d\u092f \u0932\u0921\u093c\u0915\u0947 \u0915\u093e \u0935\u094d\u0939\u0940\u0932\u091a\u0947\u092f\u0930 \u092a\u0930\u0964<br>\n\u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928 \u092c\u0932 \u0915\u0947 \u0935\u093f\u092a\u0930\u0940\u0924 \u0924\u094b \u090b\u0923\u093e\u0924\u094d\u092e\u0915 - \u0917\u094b\u0932\u0915\u0940\u092a\u0930 \u0917\u0947\u0902\u0926 \u0930\u094b\u0915\u0924\u093e \u091a\u093f\u0924\u094d\u0930 7.7b \u092c\u0932 \u0917\u0924\u093f \u0915\u0947 \u0935\u093f\u092a\u0930\u0940\u0924 \u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928 \u0935\u093f\u092a\u0930\u0940\u0924 \u090b\u0923\u093e\u0924\u094d\u092e\u0915 \u0915\u093e\u0930\u094d\u092f \u0917\u094b\u0932\u0915\u0940\u092a\u0930 \u0915\u093e \u0917\u0947\u0902\u0926 \u092a\u0930\u0964<br><br>\n\n<b>\u0909\u0926\u093e\u0939\u0930\u0923 7.1 \u0921\u0902\u092c\u0932:<\/b><br>\n\u0932\u0921\u093c\u0915\u0940 \u0921\u0902\u092c\u0932 \u0909\u0920\u093e\u0924\u0940 \u0935\u091c\u0928 \u0915\u0947 \u092c\u0930\u093e\u092c\u0930 \u092c\u0932 \u090a\u092a\u0930 \u0932\u0947 \u091c\u093e\u0924\u0947 \u092c\u0932 \u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928 same \u0927\u0928\u093e\u0924\u094d\u092e\u0915 \u0915\u093e\u0930\u094d\u092f\u0964 \u0928\u0940\u091a\u0947 \u0932\u093e\u0924\u0947 \u092a\u0915\u0921\u093c\u0928\u0947 \u0915\u0947 \u0932\u093f\u090f \u092c\u0932 \u0935\u093f\u092a\u0930\u0940\u0924 \u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928 \u090b\u0923\u093e\u0924\u094d\u092e\u0915 \u0915\u093e\u0930\u094d\u092f\u0964<br><br>\n\n<b>\u0909\u0926\u093e\u0939\u0930\u0923 7.2 \u0917\u094b\u0932\u0915\u0940\u092a\u0930:<\/b><br>\n\u0939\u093e\u0925 15 cm \u092a\u0940\u091b\u0947 0.15 m \u092c\u0932 200 N - \u0915\u093e\u0930\u094d\u092f = F\u00d7s =200\u00d7(-0.15)= -30 J - \u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928 \u090b\u0923\u093e\u0924\u094d\u092e\u0915 \u0915\u094d\u092f\u094b\u0902\u0915\u093f \u0917\u0947\u0902\u0926 \u0917\u0924\u093f \u0926\u093f\u0936\u093e \u092c\u0932 \u0915\u0947 \u0935\u093f\u092a\u0930\u0940\u0924\u0964<br>\n\u0928\u094b\u091f: \u0917\u0947\u0902\u0926 \u0914\u0930 \u0917\u094b\u0932\u0915\u0940\u092a\u0930 \u0926\u094b\u0928\u094b\u0902 \u092c\u0930\u093e\u092c\u0930 \u0935\u093f\u092a\u0930\u0940\u0924 \u092c\u0932 \u0932\u0917\u093e\u0924\u0947 \u0926\u094b\u0928\u094b\u0902 \u090f\u0915 \u0926\u0942\u0938\u0930\u0947 \u092a\u0930 \u0915\u093e\u0930\u094d\u092f \u0915\u0930\u0924\u0947 - \u0917\u0947\u0902\u0926 \u0927\u0928\u093e\u0924\u094d\u092e\u0915 \u0915\u093e\u0930\u094d\u092f \u0917\u094b\u0932\u0915\u0940\u092a\u0930 \u092a\u0930 \u0917\u094b\u0932\u0915\u0940\u092a\u0930 \u090b\u0923\u093e\u0924\u094d\u092e\u0915 \u0917\u0947\u0902\u0926 \u092a\u0930\u0964<br><br>\n\n<b>\u0938\u094b\u091a\u094b \u0914\u0930 \u092c\u0924\u093e\u0913 Q1-2 \u092a\u0947\u091c 119:<\/b><br>\nQ1 \u092a\u093f\u091b\u0932\u0947 \u0905\u0927\u094d\u092f\u093e\u092f \u092e\u0947\u0902 \u092d\u093e\u0930\u094b\u0924\u094d\u0924\u094b\u0932\u0915 \u092c\u093e\u0930\u092c\u0947\u0932 \u0938\u094d\u0925\u093f\u0930 \u092a\u0915\u0921\u093c\u0947 \u0915\u094d\u092f\u093e \u0915\u093e\u0930\u094d\u092f \u0915\u0930 \u0930\u0939\u0940? \u0928\u0939\u0940\u0902 s=0 \u0907\u0938\u0932\u093f\u090f W=0<br>\nQ2 \u0938\u093f\u0915\u094d\u0915\u094b\u0902 \u0915\u0940 \u0922\u0947\u0930\u0940 \u0916\u0941\u0930\u0926\u0930\u0940 \u0938\u0924\u0939 \u091a\u093f\u0924\u094d\u0930 6.13c \u092a\u0930 \u0918\u0930\u094d\u0937\u0923 \u0926\u094d\u0935\u093e\u0930\u093e \u0915\u093e\u0930\u094d\u092f \u0927\u0928\u093e\u0924\u094d\u092e\u0915 \u090b\u0923\u093e\u0924\u094d\u092e\u0915 \u0936\u0942\u0928\u094d\u092f? \u090b\u0923\u093e\u0924\u094d\u092e\u0915 - \u0918\u0930\u094d\u0937\u0923 \u0917\u0924\u093f \u0915\u0947 \u0935\u093f\u092a\u0930\u0940\u0924\u0964<br>\n\n<\/div><\/div>\n\n<div id=\"c7h-3\" style=\"display:none;\"><div style=\"background:#2e7d32;color:#fff;padding:6px 14px;border-radius:20px;font-size:13px;font-weight:bold;display:inline-block;margin-bottom:8px;\">\ud83d\udfe2 \u092d\u093e\u0917 3\/5 - \u0915\u093e\u0930\u094d\u092f-\u090a\u0930\u094d\u091c\u093e \u092a\u094d\u0930\u092e\u0947\u092f \u0914\u0930 \u090a\u0930\u094d\u091c\u093e \u0915\u0947 \u0930\u0942\u092a<\/div><div style=\"background:#fff;border:1.5px solid #bf360c;border-radius:10px;padding:12px;font-size:14px;line-height:1.9;height:580px;overflow-y:auto;\">\n\n<b>7.2 \u0915\u093e\u0930\u094d\u092f-\u090a\u0930\u094d\u091c\u093e \u092a\u094d\u0930\u092e\u0947\u092f - \u092a\u0947\u091c 120 \u091a\u093f\u0924\u094d\u0930 7.8 \u091a\u093f\u0924\u094d\u0930 7.9:<\/b><br>\n\u091c\u092c \u092c\u0932 \u0932\u0917\u093e \u0935\u0938\u094d\u0924\u0941 \u0939\u091f\u0940 \u0915\u093e\u0930\u094d\u092f \u0939\u0941\u0906 \u0915\u094d\u092f\u093e \u0935\u0938\u094d\u0924\u0941 \u0928\u0947 \u0914\u0930 \u0915\u093e\u0930\u094d\u092f \u0915\u0930\u0928\u0947 \u0915\u0940 \u0915\u094d\u0937\u092e\u0924\u093e \u092a\u093e\u0908?<br>\n\u092b\u0940\u0932\u094d\u0921\u0930 \u0915\u094d\u0930\u093f\u0915\u0947\u091f \u0917\u0947\u0902\u0926 \u0935\u093f\u0915\u0947\u091f \u0915\u0940 \u0913\u0930 \u092b\u0947\u0902\u0915\u0924\u093e \u091a\u093f\u0924\u094d\u0930 7.8a \u091a\u0932\u0924\u0940 \u0917\u0947\u0902\u0926 \u0935\u093f\u0915\u0947\u091f \u0917\u093f\u0930\u093e\u0924\u0940 \u091a\u093f\u0924\u094d\u0930 7.8b, \u0917\u092e\u0932\u093e \u090a\u0901\u091a\u093e\u0908 \u0938\u0947 \u0917\u093f\u0930 \u0928\u0940\u091a\u0947 \u0935\u0938\u094d\u0924\u0941 \u091f\u0942\u091f\u0924\u0940 \u091a\u093f\u0924\u094d\u0930 7.8c - \u0917\u0947\u0902\u0926 \u092f\u093e \u0917\u092e\u0932\u0947 \u0928\u0947 \u0915\u093e\u0930\u094d\u092f \u0915\u0930\u0928\u0947 \u0915\u0940 \u0915\u094d\u0937\u092e\u0924\u093e \u092a\u093e\u0908\u0964<br>\n<b>\u092a\u0930\u093f\u092d\u093e\u0937\u093e: \u0915\u093e\u0930\u094d\u092f \u0915\u0930\u0928\u0947 \u0915\u0940 \u0915\u094d\u0937\u092e\u0924\u093e \u0930\u0916\u0928\u0947 \u0935\u093e\u0932\u0940 \u0935\u0938\u094d\u0924\u0941 \u092e\u0947\u0902 \u090a\u0930\u094d\u091c\u093e \u0939\u094b\u0924\u0940 \u0939\u0948\u0964 \u0917\u0947\u0902\u0926 \u0928\u0947 \u092b\u0940\u0932\u094d\u0921\u0930 \u0915\u0947 \u0915\u093e\u0930\u094d\u092f \u0938\u0947 \u090a\u0930\u094d\u091c\u093e \u092a\u093e\u0908 \u0917\u092e\u0932\u0947 \u0928\u0947 \u090a\u0901\u091a\u093e\u0908 \u0924\u0915 \u0909\u0920\u093e\u0928\u0947 \u0915\u0947 \u0915\u093e\u0930\u094d\u092f \u0938\u0947\u0964 \u0927\u0928\u093e\u0924\u094d\u092e\u0915 \u0915\u093e\u0930\u094d\u092f \u0939\u094b\u0928\u0947 \u092a\u0930 \u090a\u0930\u094d\u091c\u093e \u092c\u0922\u093c\u0924\u0940 \u092b\u093f\u0930 \u0935\u0938\u094d\u0924\u0941 \u0926\u0942\u0938\u0930\u0940 \u0935\u0938\u094d\u0924\u0941 \u092a\u0930 \u092c\u0932 \u0932\u0917\u093e\u0915\u0930 \u0939\u091f\u093e\u0915\u0930 \u090a\u0930\u094d\u091c\u093e \u0938\u094d\u0925\u093e\u0928\u093e\u0902\u0924\u0930\u093f\u0924 \u0915\u0930 \u0938\u0915\u0924\u0940 - \u0917\u0947\u0902\u0926 \u0935\u093f\u0915\u0947\u091f \u0915\u094b \u0939\u091f\u093e\u0924\u0940 \u090a\u0930\u094d\u091c\u093e \u0938\u094d\u0925\u093e\u0928\u093e\u0902\u0924\u0930\u0923\u0964<\/b><br>\n<b>\u0935\u0938\u094d\u0924\u0941 \u092a\u0930 \u0915\u093f\u092f\u093e \u0917\u092f\u093e \u0915\u093e\u0930\u094d\u092f = \u0909\u0938\u0915\u0940 \u090a\u0930\u094d\u091c\u093e \u092e\u0947\u0902 \u092a\u0930\u093f\u0935\u0930\u094d\u0924\u0928 \u0938\u092e\u0940\u0915\u0930\u0923 7.3 - \u092a\u094d\u0930\u092e\u0947\u092f - \u0928\u093f\u0915\u093e\u092f \u092f\u093e \u092c\u0926\u0932\u0924\u0947 \u092c\u0932\u094b\u0902 \u092a\u0930 \u092d\u0940 \u0938\u0924\u094d\u092f - \u0915\u0920\u093f\u0928 \u0938\u092e\u0938\u094d\u092f\u093e\u090f\u0901 \u0939\u0932 \u0915\u0930\u0928\u0947 \u092e\u0947\u0902 \u092e\u0926\u0926\u0964 SI \u092e\u093e\u0924\u094d\u0930\u0915 \u091c\u0942\u0932 J\u0964 \u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 \u0915\u093e\u0930\u094d\u092f \u090a\u0930\u094d\u091c\u093e \u0938\u094d\u0925\u093e\u0928\u093e\u0902\u0924\u0930\u0923 \u0915\u093e \u090f\u0915 \u0924\u0930\u0940\u0915\u093e\u0964 \u0905\u0928\u094d\u092f \u0924\u0930\u0940\u0915\u0947 \u090a\u0937\u094d\u092e\u093e - \u0926\u094b \u0935\u0938\u094d\u0924\u0941 \u0905\u0932\u0917 \u0924\u093e\u092a\u092e\u093e\u0928 \u0938\u0902\u092a\u0930\u094d\u0915 \u092e\u0947\u0902 \u0917\u0930\u092e \u0938\u0947 \u0920\u0902\u0921\u0940 \u092e\u0947\u0902 \u090a\u0930\u094d\u091c\u093e \u092c\u0939\u093e\u0935\u0964 \u092c\u093f\u0928\u093e \u0938\u0902\u092a\u0930\u094d\u0915 \u0935\u093f\u0915\u093f\u0930\u0923 \u0938\u0942\u0930\u094d\u092f \u0915\u0940 \u090a\u0930\u094d\u091c\u093e \u092a\u0943\u0925\u094d\u0935\u0940, \u092c\u093f\u091c\u0932\u0940 \u0938\u0930\u094d\u0915\u093f\u091f, \u0927\u094d\u0935\u0928\u093f \u0924\u0930\u0902\u0917\u0947\u0902, \u0928\u093e\u092d\u093f\u0915\u0940\u092f \u0905\u092d\u093f\u0915\u094d\u0930\u093f\u092f\u093e\u090f\u0901 \u0938\u0942\u0930\u094d\u092f \u0936\u0915\u094d\u0924\u093f\u0964<\/b><br><br>\n\n<b>\u0909\u0926\u093e\u0939\u0930\u0923 7.3 \u0915\u0948\u0930\u092e:<\/b><br>\n\u0938\u094d\u091f\u094d\u0930\u093e\u0907\u0915\u0930 \u091a\u0932\u0924\u093e \u0938\u092b\u0947\u0926 \u0917\u094b\u091f\u0940 \u0938\u0947 \u091f\u0915\u0930\u093e\u0924\u093e \u0938\u092b\u0947\u0926 \u0915\u093e\u0932\u0940 \u0938\u0947 - \u0938\u094d\u091f\u094d\u0930\u093e\u0907\u0915\u0930 \u0938\u092b\u0947\u0926 \u092a\u0930 \u0927\u0928\u093e\u0924\u094d\u092e\u0915 \u0915\u093e\u0930\u094d\u092f \u090a\u0930\u094d\u091c\u093e \u092c\u0922\u093c\u0940 \u0938\u092b\u0947\u0926 \u0938\u094d\u091f\u094d\u0930\u093e\u0907\u0915\u0930 \u092a\u0930 \u0935\u093f\u092a\u0930\u0940\u0924 \u092c\u0932 \u090b\u0923\u093e\u0924\u094d\u092e\u0915 \u0915\u093e\u0930\u094d\u092f \u090a\u0930\u094d\u091c\u093e \u0918\u091f\u0940\u0964 \u0935\u0948\u0938\u0947 \u0939\u0940 \u0938\u092b\u0947\u0926 \u0915\u093e\u0932\u0940 \u092a\u0930 \u0927\u0928\u093e\u0924\u094d\u092e\u0915 \u0938\u092b\u0947\u0926 \u090a\u0930\u094d\u091c\u093e \u092c\u0922\u093c\u0940 \u0915\u093e\u0932\u0940 \u0938\u092b\u0947\u0926 \u092a\u0930 \u090b\u0923\u093e\u0924\u094d\u092e\u0915 \u0918\u091f\u0940\u0964<br><br>\n\n<b>7.3 \u090a\u0930\u094d\u091c\u093e \u0915\u0947 \u0930\u0942\u092a - \u091a\u093f\u0924\u094d\u0930 7.10 \u092a\u0947\u091c 121:<\/b><br>\n\u090a\u0930\u094d\u091c\u093e \u0915\u093e\u0930\u094d\u092f \u0915\u0930\u0928\u0947 \u0915\u0940 \u0915\u094d\u0937\u092e\u0924\u093e - \u0905\u092d\u0940 \u0924\u0915 \u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 \u090a\u0930\u094d\u091c\u093e\u0964 \u090a\u0930\u094d\u091c\u093e \u0915\u0908 \u0930\u0942\u092a\u094b\u0902 \u092e\u0947\u0902 - \u091a\u093f\u0924\u094d\u0930 7.10 \u0905\u0932\u0917-\u0905\u0932\u0917 \u0930\u0942\u092a:<br>\n- \u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 \u090a\u0930\u094d\u091c\u093e - \u0935\u0938\u094d\u0924\u0941\u0913\u0902 \u0915\u0940 \u0917\u0924\u093f \u092f\u093e \u0938\u094d\u0925\u093f\u0924\u093f<br>\n- \u090a\u0937\u094d\u092e\u0940\u092f \u090a\u0930\u094d\u091c\u093e - \u0917\u0930\u092e \u092f\u093e \u0917\u0930\u094d\u092e<br>\n- \u092a\u094d\u0930\u0915\u093e\u0936 \u090a\u0930\u094d\u091c\u093e - \u091c\u093f\u0938\u0938\u0947 \u0939\u092e \u0926\u0947\u0916 \u092a\u093e\u0924\u0947 \u0939\u0948\u0902<br>\n- \u0927\u094d\u0935\u0928\u093f \u090a\u0930\u094d\u091c\u093e - \u0939\u0935\u093e \u0915\u0947 \u0915\u0923\u094b\u0902 \u0915\u093e \u0915\u0902\u092a\u0928<br>\n- \u0935\u093f\u0926\u094d\u092f\u0941\u0924 \u090a\u0930\u094d\u091c\u093e - \u0906\u0935\u0947\u0936\u094b\u0902 \u0915\u0940 \u0938\u094d\u0925\u093f\u0924\u093f \u092f\u093e \u0917\u0924\u093f<br>\n- \u0928\u093e\u092d\u093f\u0915\u0940\u092f \u090a\u0930\u094d\u091c\u093e - \u092a\u0930\u092e\u093e\u0923\u0941\u0913\u0902 \u0915\u0947 \u0928\u093e\u092d\u093f\u0915<br>\n- \u0930\u093e\u0938\u093e\u092f\u0928\u093f\u0915 \u090a\u0930\u094d\u091c\u093e - \u0908\u0902\u0927\u0928 \u092d\u094b\u091c\u0928 \u092a\u0930\u092e\u093e\u0923\u0941\u0913\u0902 \u0915\u0947 \u0930\u093e\u0938\u093e\u092f\u0928\u093f\u0915 \u092c\u0902\u0927<br>\n\u090f\u0915 \u0930\u0942\u092a \u0938\u0947 \u0926\u0942\u0938\u0930\u0947 \u092e\u0947\u0902 \u092c\u0926\u0932\u0928\u093e \u0938\u0902\u092d\u0935 - \u092c\u093f\u091c\u0932\u0940 \u2192 \u092c\u0932\u094d\u092c \u092e\u0947\u0902 \u2192 \u092a\u094d\u0930\u0915\u093e\u0936 \u090a\u0937\u094d\u092e\u093e \u2192 \u0935\u093e\u091f\u0930 \u0939\u0940\u091f\u0930 \u092e\u0947\u0902 \u090a\u0937\u094d\u092e\u093e, \u0930\u093e\u0938\u093e\u092f\u0928\u093f\u0915 \u092d\u094b\u091c\u0928 \u2192 \u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 \u092e\u093e\u0902\u0938\u092a\u0947\u0936\u093f\u092f\u093e\u0901, \u0918\u0902\u091f\u0940 \u092c\u091c\u0928\u093e \u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 \u2192 \u0927\u094d\u0935\u0928\u093f\u0964<br><br>\n\n<b>Q3 \u0938\u094b\u091a\u094b \u0914\u0930 \u092c\u0924\u093e\u0913 \u092a\u0947\u091c 121: \u0938\u093e\u0907\u0915\u093f\u0932 \u0938\u092e\u0924\u0932 \u0938\u0921\u093c\u0915 \u092a\u0930 \u092e\u093e\u0902\u0938\u092a\u0947\u0936\u093f\u092f\u094b\u0902 \u0915\u0940 \u090a\u0930\u094d\u091c\u093e \u0915\u093f\u0928 \u0930\u0942\u092a\u094b\u0902 \u092e\u0947\u0902 \u0926\u093f\u0916\u0924\u0940?<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: \u092e\u093e\u0902\u0938\u092a\u0947\u0936\u0940 \u0930\u093e\u0938\u093e\u092f\u0928\u093f\u0915 \u2192 \u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 \u0938\u093e\u0907\u0915\u093f\u0932 \u0917\u0924\u093f\u091c + \u090a\u0937\u094d\u092e\u0940\u092f \u0918\u0930\u094d\u0937\u0923 + \u0927\u094d\u0935\u0928\u093f\u0964<\/b><br>\n\n<\/div><\/div>\n\n<div id=\"c7h-4\" style=\"display:none;\"><div style=\"background:#ef6c00;color:#fff;padding:6px 14px;border-radius:20px;font-size:13px;font-weight:bold;display:inline-block;margin-bottom:8px;\">\ud83d\udfe0 \u092d\u093e\u0917 4\/5 - \u0917\u0924\u093f\u091c \u090a\u0930\u094d\u091c\u093e \u0914\u0930 \u0938\u094d\u0925\u093f\u0924\u093f\u091c \u090a\u0930\u094d\u091c\u093e<\/div><div style=\"background:#fff;border:1.5px solid #bf360c;border-radius:10px;padding:12px;font-size:14px;line-height:1.9;height:580px;overflow-y:auto;\">\n\n<b>7.4 \u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 \u090a\u0930\u094d\u091c\u093e - \u092a\u0947\u091c 121 - \u0917\u0924\u093f \u092f\u093e \u0938\u094d\u0925\u093f\u0924\u093f \u0915\u0947 \u0915\u093e\u0930\u0923 \u090a\u0930\u094d\u091c\u093e:<\/b><br>\n\n<b>7.4.1 \u0917\u0924\u093f\u091c \u090a\u0930\u094d\u091c\u093e - \u092a\u0930\u093f\u092d\u093e\u0937\u093e - \u091a\u093f\u0924\u094d\u0930 7.11:<\/b><br>\n\u0917\u0924\u093f \u0915\u0947 \u0915\u093e\u0930\u0923 \u0935\u0938\u094d\u0924\u0941 \u092e\u0947\u0902 \u090a\u0930\u094d\u091c\u093e - \u0938\u092d\u0940 \u091a\u0932\u0924\u0940 \u0935\u0938\u094d\u0924\u0941\u090f\u0901 \u0938\u093e\u0907\u0915\u093f\u0932 \u0932\u0941\u0922\u093c\u0915\u0924\u0940 \u0917\u0947\u0902\u0926 \u092e\u0947\u0902\u0964<br>\n\u0938\u094d\u0925\u093f\u0930 \u0935\u0938\u094d\u0924\u0941 \u0915\u0940 \u0917\u0924\u093f\u091c \u0936\u0942\u0928\u094d\u092f \u092e\u093e\u0928\u0924\u0947\u0964 \u0935\u093f\u0930\u093e\u092e \u0938\u0947 \u0936\u0941\u0930\u0942 \u092c\u0932 F \u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928 s \u0905\u0902\u0924\u093f\u092e \u0935\u0947\u0917 v \u0905\u0902\u0924\u093f\u092e \u0917\u0924\u093f\u091c K - \u0915\u093f\u092f\u093e \u0917\u092f\u093e \u0915\u093e\u0930\u094d\u092f W=F\u00d7s\u0964<br>\n<b>\u0938\u0942\u0924\u094d\u0930 \u0928\u093f\u0915\u093e\u0932\u0928\u093e - \u092a\u0947\u091c 122 \u0938\u092e\u0940\u0915\u0930\u0923 7.4-7.6:<\/b><br>\n\u092a\u094d\u0930\u093e\u0930\u0902\u092d\u093f\u0915 u \u0905\u0902\u0924\u093f\u092e v \u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928 s \u0928\u093f\u092f\u0924 \u092c\u0932 F \u0924\u094d\u0935\u0930\u0923 a \u0928\u093f\u092f\u0924 \u0917\u0924\u093f \u0938\u092e\u0940\u0915\u0930\u0923 v\u00b2=u\u00b2+2as \u2192 s=(v\u00b2-u\u00b2)\/2a \u0938\u092e\u0940\u0915\u0930\u0923 7.4<br>\nW=F\u00d7s=ma\u00d7s = ma\u00d7(v\u00b2-u\u00b2)\/2a = (1\/2)m(v\u00b2-u\u00b2) = (1\/2)mv\u00b2 - (1\/2)mu\u00b2 \u0938\u092e\u0940\u0915\u0930\u0923 7.5 - \u0915\u093e\u0930\u094d\u092f-\u090a\u0930\u094d\u091c\u093e \u092a\u094d\u0930\u092e\u0947\u092f \u0938\u0947 \u0915\u093e\u0930\u094d\u092f \u090a\u0930\u094d\u091c\u093e \u092e\u0947\u0902 \u092a\u0930\u093f\u0935\u0930\u094d\u0924\u0928\u0964<br>\n\u092f\u0926\u093f u=0 \u0924\u094b \u092a\u0930\u093f\u0935\u0930\u094d\u0924\u0928 \u0905\u0902\u0924\u093f\u092e \u0917\u0924\u093f\u091c - \u0907\u0938\u0932\u093f\u090f <b>\u0917\u0924\u093f\u091c \u090a\u0930\u094d\u091c\u093e K = (1\/2)mv\u00b2 \u0938\u092e\u0940\u0915\u0930\u0923 7.6<\/b> - SI \u091c\u0942\u0932 J - \u0926\u093f\u0936\u093e \u0928\u0939\u0940\u0902\u0964 \u0927\u0928\u093e\u0924\u094d\u092e\u0915 \u0915\u093e\u0930\u094d\u092f \u0935\u0947\u0917 \u092c\u0922\u093c\u093e \u0917\u0924\u093f\u091c \u092c\u0922\u093c\u0940, \u090b\u0923\u093e\u0924\u094d\u092e\u0915 \u0915\u093e\u0930\u094d\u092f \u0935\u0947\u0917 \u0918\u091f\u093e \u0917\u0924\u093f\u091c \u0918\u091f\u0940, W=0 \u0935\u0947\u0917 \u0928\u0939\u0940\u0902 \u092c\u0926\u0932\u093e \u0917\u0924\u093f\u091c \u0938\u094d\u0925\u093f\u0930\u0964<br><br>\n\n<b>\u0909\u0926\u093e\u0939\u0930\u0923 7.4 \u0935\u0947\u0917 \u0926\u094b\u0917\u0941\u0928\u093e \u0917\u0924\u093f\u091c?<\/b><br>\n\u0926\u094d\u0930\u0935\u094d\u092f\u092e\u093e\u0928 m \u0935\u0947\u0917 v K=\u00bdmv\u00b2, \u0935\u0947\u0917 2v K=\u00bdm(2v)\u00b2=4\u00d7\u00bdmv\u00b2 \u21924 \u0917\u0941\u0928\u093e\u0964<br><br>\n\n<b>\u0909\u0926\u093e\u0939\u0930\u0923 7.5 \u0915\u094d\u0930\u093f\u0915\u0947\u091f\u0930 \u0917\u0947\u0902\u0926 0.2 kg 154.8 km\/h =43 m\/s:<\/b><br>\nK=\u00bd\u00d70.2\u00d743\u00b2 =0.1\u00d71849=184.9 J<br><br>\n\n<b>\u0909\u0926\u093e\u0939\u0930\u0923 7.6 \u091c\u0947\u091f \u0935\u093f\u092e\u093e\u0928 15000 kg \u0921\u0947\u0915 367500 N 100 m \u092e\u0947\u0902 \u0930\u094b\u0915\u0928\u093e \u0935\u0947\u0917 \u0915\u094d\u092f\u093e? - \u092a\u0947\u091c123 \u091a\u093f\u0924\u094d\u0930 7.12:<\/b><br>\n\u092a\u094d\u0930\u093e\u0930\u0902\u092d\u093f\u0915 K=\u00bd\u00d715000\u00d7v\u00b2 \u0905\u0902\u0924\u093f\u092e 0 \u092a\u0930\u093f\u0935\u0930\u094d\u0924\u0928= -\u00bd\u00d715000\u00d7v\u00b2 \u0924\u093e\u0930 \u0915\u093e \u0915\u093e\u0930\u094d\u092f=F\u00d7s=367500\u00d7(-100) \u090b\u0923\u093e\u0924\u094d\u092e\u0915 \u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928 \u092c\u0932 \u0915\u0947 \u0935\u093f\u092a\u0930\u0940\u0924 -\u00bd\u00d715000\u00d7v\u00b2= -367500\u00d7100 \u2192v\u00b2=36750\u00d72\/15? \u0905\u0938\u0932 \u092e\u0947\u0902 367500\u00d7100\u00d72\/15000=73500000\/15000=4900 \u2192v=70 m\/s =252 km\/h\u0964<br><br>\n\n<b>\u0938\u094b\u091a\u094b \u0914\u0930 \u092c\u0924\u093e\u0913 Q4-5 \u092a\u0947\u091c123:<\/b><br>\nQ4 \u0926\u094d\u0930\u0935\u094d\u092f\u092e\u093e\u0928 m \u0914\u0930 4m same \u0917\u0924\u093f\u091c \u0905\u0928\u0941\u092a\u093e\u0924 \u0935\u0947\u0917? K same \u00bdmvA\u00b2=\u00bd\u00d74m\u00d7vB\u00b2 \u2192vA\u00b2=4vB\u00b2 \u2192vA\/vB=2\/1 \u21922:1<br>\nQ5 \u0928\u093f\u092f\u0924 \u0935\u0947\u0917 \u0917\u0924\u093f\u091c \u0938\u094d\u0925\u093f\u0924\u093f \u0915\u0947 \u0938\u093e\u0925 \u092c\u0926\u0932\u0947? \u0928\u0939\u0940\u0902 \u092f\u0926\u093f \u0935\u0947\u0917 \u0928\u093f\u092f\u0924 \u0917\u0924\u093f\u091c same \u0938\u094d\u0925\u093f\u0924\u093f \u0938\u0947 \u0938\u094d\u0935\u0924\u0902\u0924\u094d\u0930\u0964<br><br>\n\n<b>7.4.2 \u0938\u094d\u0925\u093f\u0924\u093f\u091c \u090a\u0930\u094d\u091c\u093e - \u091a\u093f\u0924\u094d\u0930 7.13-7.18 - \u092a\u0947\u091c123-126:<\/b><br>\n\u0905\u0927\u094d\u092f\u093e\u092f 6 \u0917\u0924\u093f\u0935\u093f\u0927\u093f 6.1 \u0938\u093f\u0915\u094d\u0915\u094b\u0902 \u0915\u0940 \u0922\u0947\u0930\u0940 \u0916\u093f\u0902\u091a\u0940 \u0930\u092c\u0930 \u092c\u0948\u0902\u0921 \u091b\u094b\u0921\u093c\u0928\u0947 \u092a\u0930 \u0939\u091f\u093e\u0924\u0940\u0964 \u0917\u0941\u0932\u0947\u0932 \u091a\u093f\u0924\u094d\u0930 7.13a \u0916\u093f\u0902\u091a\u093e \u0907\u0932\u093e\u0938\u094d\u091f\u093f\u0915 \u092c\u0948\u0902\u0921 \u091b\u094b\u0921\u093c\u0928\u0947 \u092a\u0930 \u0935\u0938\u094d\u0924\u0941 \u0906\u0917\u0947, \u0924\u0940\u0930\u0902\u0926\u093e\u091c\u0940 \u091a\u093f\u0924\u094d\u0930 7.13b \u0924\u0940\u0930\u0902\u0926\u093e\u091c \u0927\u0928\u0941\u0937 \u0915\u0940 \u0921\u094b\u0930\u0940 \u0916\u0940\u0902\u091a \u092d\u0941\u091c\u093e\u090f\u0901 \u092e\u094b\u0921\u093c \u091b\u094b\u0921\u093c\u0928\u0947 \u092a\u0930 \u0927\u0928\u0941\u0937 \u0935\u093e\u092a\u0938 \u0924\u0940\u0930 \u0909\u0921\u093c\u0924\u093e\u0964<br>\n\u0916\u093f\u0902\u091a\u093e \u092c\u0948\u0902\u0921 \u092e\u0941\u0921\u093c\u093e \u0927\u0928\u0941\u0937 \u091b\u094b\u0921\u093c\u0928\u0947 \u092a\u0930 \u0935\u0938\u094d\u0924\u0941 \u092a\u0930 \u092c\u0932 \u0932\u0917\u093e\u0924\u0947 \u0917\u0924\u093f \u0917\u0924\u093f\u091c \u0926\u0947\u0924\u0947 same time \u092c\u0948\u0902\u0921 \u0927\u0928\u0941\u0937 \u0935\u093e\u092a\u0938\u0964 \u0938\u093f\u0915\u094d\u0915\u0947 \u0917\u0947\u0902\u0926 \u0924\u0940\u0930 \u0917\u0924\u093f\u091c \u092a\u093e\u0908 \u091c\u094b \u092a\u0939\u0932\u0947 \u0928\u0939\u0940\u0902 \u0925\u0940 - \u092f\u0939 \u090a\u0930\u094d\u091c\u093e \u0916\u093f\u0902\u091a\u0947 \u092c\u0948\u0902\u0921 \u092e\u0941\u0921\u093c\u0947 \u0927\u0928\u0941\u0937 \u0938\u0947 \u0906\u0908 \u091c\u094b \u0906\u0915\u093e\u0930 \u0915\u0947 \u0915\u093e\u0930\u0923 \u0915\u093e\u0930\u094d\u092f \u0915\u0930\u0928\u0947 \u0915\u0940 \u0915\u094d\u0937\u092e\u0924\u093e \u0930\u0916\u0924\u0947\u0964 \u0935\u093f\u0930\u0942\u092a\u0923 \u0915\u0930\u0928\u0947 \u0935\u093e\u0932\u0947 \u092c\u0932 \u0915\u093e \u0915\u093e\u0930\u094d\u092f \u092c\u0948\u0902\u0921 \u0927\u0928\u0941\u0937 \u092e\u0947\u0902 \u091c\u092e\u093e\u0964<br>\n\u0938\u094d\u092a\u094d\u0930\u093f\u0902\u0917 \u0916\u093f\u0902\u091a\u0928\u093e \u0926\u092c\u0928\u093e \u091a\u093f\u0924\u094d\u0930 7.14a \u0915\u093e\u0930\u094d\u092f \u0906\u0915\u093e\u0930 \u092c\u0926\u0932\u0928\u093e \u0935\u093f\u0930\u0942\u092a\u0923 \u091a\u093f\u0924\u094d\u0930 7.14b \u090a\u0930\u094d\u091c\u093e \u091c\u092e\u093e \u0935\u093f\u0928\u094d\u092f\u093e\u0938 \u0906\u0915\u093e\u0930 \u0915\u0947 \u0915\u093e\u0930\u0923\u0964 \u091b\u094b\u0921\u093c\u0928\u0947 \u092a\u0930 \u091a\u093f\u0924\u094d\u0930 7.14c \u0935\u093e\u092a\u0938 \u0906\u0915\u093e\u0930 \u091c\u092e\u093e \u090a\u0930\u094d\u091c\u093e \u0917\u0924\u093f\u091c \u0935\u0938\u094d\u0924\u0941 \u0938\u0902\u092a\u0930\u094d\u0915\u0964 \u092c\u093e\u0939\u0930\u0940 \u092c\u0932 \u0905\u0902\u0926\u0930\u0942\u0928\u0940 \u092c\u0932\u094b\u0902 \u0915\u094b \u0939\u0930\u093e\u0915\u0930 \u0935\u093f\u0930\u0942\u092a\u0923 \u0915\u0930\u0924\u093e \u092c\u093e\u0939\u0930\u0940 \u092c\u0932 \u0939\u091f\u093e\u0928\u0947 \u092a\u0930 \u0905\u0902\u0926\u0930\u0942\u0928\u0940 \u092c\u0932 \u0935\u093f\u0930\u0942\u092a\u0923 \u0939\u091f\u093e\u0915\u0930 \u0915\u093e\u0930\u094d\u092f \u0915\u0930 \u0938\u0915\u0924\u0947 \u0905\u0902\u0926\u0930\u0942\u0928\u0940 \u092c\u0932 \u090a\u0930\u094d\u091c\u093e \u091c\u092e\u093e \u0915\u0930\u0928\u0947 \u0926\u0947\u0924\u0947\u0964<br>\n\u091a\u0941\u0902\u092c\u0915 \u0938\u092e\u093e\u0928 \u0927\u094d\u0930\u0941\u0935 \u092a\u094d\u0930\u0924\u093f\u0915\u0930\u094d\u0937\u0923 \u0935\u093f\u092a\u0930\u0940\u0924 \u0906\u0915\u0930\u094d\u0937\u0923 - \u0935\u093f\u092a\u0930\u0940\u0924 \u0927\u094d\u0930\u0941\u0935 \u0905\u0932\u0917 \u0915\u0930\u0928\u0947 \u092c\u0932 \u0932\u0917\u093e\u0928\u093e \u092a\u0921\u093c\u0924\u093e\u0964 \u0935\u093f\u092a\u0930\u0940\u0924 \u0927\u094d\u0930\u0941\u0935 \u0905\u0932\u0917 \u091b\u094b\u0921\u093c\u0928\u0947 \u092a\u0930 \u092a\u093e\u0938 \u0906\u0924\u0947 \u0917\u0924\u093f\u091c \u092a\u093e\u0908 \u092e\u091f\u0930 \u092c\u0940\u091a \u0915\u0941\u091a\u0932 \u0917\u0924\u093f\u091c \u090a\u0930\u094d\u091c\u093e \u091a\u093f\u0924\u094d\u0930 7.15a - \u0928\u093f\u0915\u093e\u092f \u0926\u094b \u091a\u0941\u0902\u092c\u0915 \u0905\u0932\u0917 \u091c\u092e\u093e \u090a\u0930\u094d\u091c\u093e \u0938\u093e\u092a\u0947\u0915\u094d\u0937 \u0938\u094d\u0925\u093f\u0924\u093f\u092f\u094b\u0902\u0964 \u0935\u0948\u0938\u0947 \u0939\u0940 \u0935\u093f\u0926\u094d\u092f\u0941\u0924 \u0906\u0935\u0947\u0936 \u091a\u093f\u0924\u094d\u0930 7.15b \u0905\u0932\u0917 \u091c\u092e\u093e \u090a\u0930\u094d\u091c\u093e \u0915\u093e\u0930\u094d\u092f \u091b\u094b\u0921\u093c\u0928\u0947 \u092a\u0930\u0964<br>\n\u0917\u0947\u0902\u0926 \u092a\u0943\u0925\u094d\u0935\u0940 \u0928\u093f\u0915\u093e\u092f \u091a\u093f\u0924\u094d\u0930 7.16 - \u0917\u0947\u0902\u0926 \u0914\u0930 \u092a\u0943\u0925\u094d\u0935\u0940 \u0906\u0915\u0930\u094d\u0937\u0923 \u092c\u0932 \u0917\u0941\u0930\u0941\u0924\u094d\u0935\u093e\u0915\u0930\u094d\u0937\u0923 \u0915\u0947 \u0935\u093f\u0930\u0941\u0926\u094d\u0927 \u0909\u0920\u093e\u0928\u0947 \u090a\u0901\u091a\u093e\u0908 \u0924\u0915 \u0915\u093e\u0930\u094d\u092f\u0964 \u0909\u0920\u093e\u0915\u0930 \u092c\u0932 \u0939\u091f\u093e\u0928\u0947 \u092a\u0930 \u0917\u0947\u0902\u0926 \u092a\u0943\u0925\u094d\u0935\u0940 \u0915\u0940 \u0913\u0930 \u0917\u0924\u093f\u091c \u092a\u093e\u0908 - \u0928\u093f\u0915\u093e\u092f \u0917\u0947\u0902\u0926 \u092a\u0943\u0925\u094d\u0935\u0940 \u0905\u0932\u0917 \u091c\u092e\u093e \u090a\u0930\u094d\u091c\u093e \u0938\u093e\u092a\u0947\u0915\u094d\u0937 \u0938\u094d\u0925\u093f\u0924\u093f\u092f\u094b\u0902\u0964<br>\n<b>\u0938\u093e\u092e\u093e\u0928\u094d\u092f\u0924\u0903 \u091c\u092c \u0928\u093f\u0915\u093e\u092f \u0935\u0938\u094d\u0924\u0941\u090f\u0901 \u092c\u0932 \u0917\u0941\u0930\u0941\u0924\u094d\u0935\u093e\u0915\u0930\u094d\u0937\u0923 \u0935\u093f\u0926\u094d\u092f\u0941\u0924 \u091a\u0941\u0902\u092c\u0915\u0940\u092f \u0938\u0947 \u092a\u0930\u0938\u094d\u092a\u0930 \u0915\u094d\u0930\u093f\u092f\u093e \u0924\u094b \u0938\u093e\u092a\u0947\u0915\u094d\u0937 \u0938\u094d\u0925\u093f\u0924\u093f\u092f\u094b\u0902 \u0915\u0947 \u0915\u093e\u0930\u0923 \u090a\u0930\u094d\u091c\u093e \u091c\u092e\u093e \u0915\u0930 \u0938\u0915\u0924\u0947\u0964<\/b><br>\n<b>\u092a\u0930\u093f\u092d\u093e\u0937\u093e: \u0938\u094d\u0925\u093f\u0924\u093f\u091c \u090a\u0930\u094d\u091c\u093e - \u0935\u0938\u094d\u0924\u0941 \u0915\u0947 \u0935\u093f\u0930\u0942\u092a\u0923 \u092a\u0930\u093f\u0923\u093e\u092e \u092f\u093e \u0928\u093f\u0915\u093e\u092f \u092e\u0947\u0902 \u0935\u0938\u094d\u0924\u0941\u0913\u0902 \u0915\u0940 \u0938\u093e\u092a\u0947\u0915\u094d\u0937 \u0938\u094d\u0925\u093f\u0924\u093f\u092f\u094b\u0902 \u0915\u0947 \u0915\u093e\u0930\u0923 \u091c\u092e\u093e \u090a\u0930\u094d\u091c\u093e\u0964<\/b><br><br>\n\n<b>\u0917\u0941\u0930\u0941\u0924\u094d\u0935\u0940\u092f \u0938\u094d\u0925\u093f\u0924\u093f\u091c \u090a\u0930\u094d\u091c\u093e - \u091a\u093f\u0924\u094d\u0930 7.17 \u091a\u093f\u0924\u094d\u0930 7.18 \u0938\u092e\u0940\u0915\u0930\u0923 7.7 \u0938\u092e\u0940\u0915\u0930\u0923 7.8 \u092a\u0947\u091c125-126:<\/b><br>\n\u092a\u0943\u0925\u094d\u0935\u0940-\u0917\u0947\u0902\u0926 \u0928\u093f\u0915\u093e\u092f \u092a\u0943\u0925\u094d\u0935\u0940 \u092c\u0939\u0941\u0924 \u092d\u093e\u0930\u0940 \u0917\u0947\u0902\u0926 \u0915\u0940 \u0913\u0930 \u092e\u0941\u0936\u094d\u0915\u093f\u0932 \u0938\u0947 \u0939\u093f\u0932\u0924\u0940 \u0909\u0926\u093e\u0939\u0930\u0923 6.8 \u0905\u0927\u094d\u092f\u093e\u092f 6 \u0907\u0938\u0932\u093f\u090f \u091c\u092e\u093e \u090a\u0930\u094d\u091c\u093e \u0905\u0915\u094d\u0938\u0930 \u0915\u0947\u0935\u0932 \u0917\u0947\u0902\u0926 \u0915\u0940 \u0917\u0941\u0930\u0941\u0924\u094d\u0935\u0940\u092f \u0938\u094d\u0925\u093f\u0924\u093f\u091c \u090a\u0930\u094d\u091c\u093e \u0915\u0939\u0940\u0964 \u0906\u092e\u0924\u094c\u0930 \u092a\u0930 \u0938\u094d\u0925\u093f\u0924\u093f\u091c \u090a\u0930\u094d\u091c\u093e \u0917\u0941\u0930\u0941\u0924\u094d\u0935\u0940\u092f \u0939\u0940\u0964<br>\n\u0917\u0924\u093f\u0935\u093f\u0927\u093f 7.1: \u092d\u093e\u0930\u0940 \u0917\u0947\u0902\u0926 \u0930\u0947\u0924 \u092d\u0930\u0947 \u092c\u0930\u094d\u0924\u0928 \u092e\u0947\u0902 1 m \u0938\u0947 \u0917\u093f\u0930\u093e\u0928\u0947 \u092a\u0930 \u0917\u0921\u094d\u0922\u093e? \u090a\u0901\u091a\u093e\u0908 2 m \u0938\u0947 \u0914\u0930 \u0917\u0939\u0930\u093e? \u0938\u092c\u0938\u0947 \u0905\u0927\u093f\u0915 \u090a\u0901\u091a\u093e\u0908 \u0938\u092c\u0938\u0947 \u0917\u0939\u0930\u093e \u0917\u0921\u094d\u0922\u093e - \u0905\u0927\u093f\u0915 \u090a\u0901\u091a\u093e\u0908 \u0909\u0920\u093e\u0928\u0947 \u0905\u0927\u093f\u0915 \u0915\u093e\u0930\u094d\u092f \u0905\u0927\u093f\u0915 \u090a\u0930\u094d\u091c\u093e \u0905\u0927\u093f\u0915 \u090a\u0901\u091a\u093e\u0908 \u0905\u0927\u093f\u0915 \u0938\u094d\u0925\u093f\u0924\u093f\u091c\u0964<br>\n\u0935\u094d\u092f\u0902\u091c\u0915 \u0915\u093e\u0930\u094d\u092f-\u090a\u0930\u094d\u091c\u093e \u092a\u094d\u0930\u092e\u0947\u092f \u0938\u0947: \u0926\u094d\u0930\u0935\u094d\u092f\u092e\u093e\u0928 m \u091c\u092e\u0940\u0928 \u092a\u0930 \u0938\u094d\u0925\u093f\u0924\u093f\u091c \u0936\u0942\u0928\u094d\u092f \u092e\u093e\u0928\u0924\u0947\u0964 \u0927\u0940\u0930\u0947-\u0927\u0940\u0930\u0947 \u090a\u0901\u091a\u093e\u0908 h \u0924\u0915 \u0909\u0920\u093e\u0928\u0947 \u092c\u0932 = mg (\u092a\u0943\u0925\u094d\u0935\u0940-\u0935\u0938\u094d\u0924\u0941 \u092c\u0932) \u0915\u093e\u0930\u094d\u092f W = \u092c\u0932 \u00d7 \u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928 = mg \u00d7 h = mgh \u0938\u092e\u0940\u0915\u0930\u0923 7.7 - \u0915\u093e\u0930\u094d\u092f-\u090a\u0930\u094d\u091c\u093e \u092a\u094d\u0930\u092e\u0947\u092f \u0938\u092e\u0940\u0915\u0930\u0923 7.3 \u0905\u0928\u0941\u0938\u093e\u0930 \u0915\u093e\u0930\u094d\u092f \u0938\u094d\u0925\u093f\u0924\u093f\u091c \u090a\u0930\u094d\u091c\u093e \u092e\u0947\u0902 \u092a\u0930\u093f\u0935\u0930\u094d\u0924\u0928 - \u0907\u0938\u0932\u093f\u090f <b>\u0938\u094d\u0925\u093f\u0924\u093f\u091c \u090a\u0930\u094d\u091c\u093e U = mgh \u0938\u092e\u0940\u0915\u0930\u0923 7.8<\/b> - \u092e\u093e\u0924\u094d\u0930\u0915 \u091c\u0942\u0932 J same \u0915\u093e\u0930\u094d\u092f \u0917\u0924\u093f\u091c\u0964<br>\n\u0909\u0926\u093e\u0939\u0930\u0923 7.7 \u092b\u0940\u0932\u094d\u0921\u0930 \u0917\u0947\u0902\u0926 200 g 10 m \u091c\u092e\u0940\u0928 \u0938\u0947 \u090a\u092a\u0930 \u0938\u094d\u0925\u093f\u0924\u093f\u091c? U=mgh=0.2\u00d710\u00d710=20 J<br>\nQ6 \u0938\u094b\u091a\u094b \u0914\u0930 \u092c\u0924\u093e\u0913 \u092a\u0947\u091c126: \u0915\u094d\u0937\u0948\u0924\u093f\u091c \u0928\u093f\u092f\u0924 \u0935\u0947\u0917 \u0938\u094d\u0925\u093f\u0924\u093f\u091c \u092c\u0926\u0932\u0947? \u0928\u0939\u0940\u0902 \u090a\u0901\u091a\u093e\u0908 same \u0907\u0938\u0932\u093f\u090f U same\u0964 \u0932\u0902\u092c\u0935\u0924 \u0927\u0940\u0930\u0947 \u0909\u0920\u093e\u0928\u093e? \u0939\u093e\u0901 \u090a\u0901\u091a\u093e\u0908 \u092c\u0922\u093c\u0940 U=mgh \u092c\u0922\u093c\u0940\u0964<br>\n\u0928\u094b\u091f: \u0905\u0902\u0926\u0930\u0942\u0928\u0940 \u092c\u0932 \u091c\u0948\u0938\u0947 \u0917\u0941\u0930\u0941\u0924\u094d\u0935\u093e\u0915\u0930\u094d\u0937\u0923 \u0935\u093f\u0926\u094d\u092f\u0941\u0924 \u091a\u0941\u0902\u092c\u0915\u0940\u092f \u0915\u0947 \u0935\u093f\u0930\u0941\u0926\u094d\u0927 \u0915\u093e\u0930\u094d\u092f \u0938\u094d\u0925\u093f\u0924\u093f\u091c \u092c\u0922\u093c\u093e\u0924\u093e \u0932\u0947\u0915\u093f\u0928 \u0938\u092d\u0940 \u0905\u0902\u0926\u0930\u0942\u0928\u0940 \u092c\u0932 \u0928\u0939\u0940\u0902 - \u0918\u0930\u094d\u0937\u0923 \u0915\u0947 \u0935\u093f\u0930\u0941\u0926\u094d\u0927 \u0915\u093e\u0930\u094d\u092f \u091c\u092e\u093e \u0928\u0939\u0940\u0902\u0964 \u090a\u0901\u091a\u0940 \u0915\u0915\u094d\u0937\u093e \u092e\u0947\u0902 \u092a\u0939\u091a\u093e\u0928\u094b\u0917\u0947\u0964<br>\n\n<\/div><\/div>\n\n<div id=\"c7h-5\" style=\"display:none;\"><div style=\"background:#004d40;color:#fff;padding:6px 14px;border-radius:20px;font-size:13px;font-weight:bold;display:inline-block;margin-bottom:8px;\">\u2705 \u092d\u093e\u0917 5\/5 - \u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 \u090a\u0930\u094d\u091c\u093e \u0938\u0902\u0930\u0915\u094d\u0937\u0923 \u0914\u0930 \u092e\u0936\u0940\u0928\u0947\u0902<\/div><div style=\"background:#fff;border:1.5px solid #bf360c;border-radius:10px;padding:12px;font-size:14px;line-height:1.9;height:580px;overflow-y:auto;\">\n\n<b>7.4.3 \u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 \u090a\u0930\u094d\u091c\u093e \u0938\u0902\u0930\u0915\u094d\u0937\u0923 - \u092a\u0947\u091c126-128 \u091a\u093f\u0924\u094d\u0930 7.19 \u091a\u093f\u0924\u094d\u0930 7.20:<\/b><br>\n\u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 \u090a\u0930\u094d\u091c\u093e = \u0917\u0924\u093f\u091c + \u0938\u094d\u0925\u093f\u0924\u093f\u091c\u0964<br>\n\u092e\u0941\u0915\u094d\u0924 \u0930\u0942\u092a \u0938\u0947 \u0917\u093f\u0930\u0928\u093e \u0909\u0926\u093e\u0939\u0930\u0923 \u092c\u093f\u0902\u0926\u0941 A \u090a\u0901\u091a\u093e\u0908 h \u092a\u094d\u0930\u093e\u0930\u0902\u092d\u093f\u0915 u=0: \u0938\u094d\u0925\u093f\u0924\u093f\u091c=mgh \u0938\u092e\u0940\u0915\u0930\u0923 7.9a \u0917\u0924\u093f\u091c=0 \u0938\u092e\u0940\u0915\u0930\u0923 7.9b \u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915=mgh \u0938\u092e\u0940\u0915\u0930\u0923 7.9c<br>\n\u0917\u093f\u0930\u0928\u0947 \u0915\u093e \u0938\u092e\u092f t \u092c\u093f\u0902\u0926\u0941 B \u0924\u0915 \u0935\u0947\u0917 v= u+gt=gt, \u090a\u0901\u091a\u093e\u0908 h' = h -\u00bdgt\u00b2 \u0917\u0924\u093f \u0938\u092e\u0940\u0915\u0930\u0923, B \u092a\u0930 \u0938\u094d\u0925\u093f\u0924\u093f\u091c = mgh' = mgh -\u00bdmgg t\u00b2, \u0917\u0924\u093f\u091c =\u00bdmv\u00b2=\u00bdm(gt)\u00b2=\u00bdmg\u00b2t\u00b2 \u0938\u092e\u0940\u0915\u0930\u0923 7.10b - \u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 = \u0938\u094d\u0925\u093f\u0924\u093f\u091c+\u0917\u0924\u093f\u091c = mgh -\u00bd... +\u00bd... =mgh \u0938\u092e\u0940\u0915\u0930\u0923 7.10c - \u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 \u0928\u093f\u092f\u0924\u0964<br>\n\u0938\u094d\u0925\u093f\u0924\u093f\u091c \u0918\u091f\u0924\u0940 \u0917\u0924\u093f\u091c \u092c\u0922\u093c\u0924\u0940 \u0916\u094b\u0908 \u0938\u094d\u0925\u093f\u0924\u093f\u091c \u0917\u0924\u093f\u091c \u092e\u0947\u0902 \u092c\u0926\u0932\u0940 \u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 \u0928\u093f\u092f\u0924 mgh - \u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 \u090a\u0930\u094d\u091c\u093e \u0938\u0902\u0930\u0915\u094d\u0937\u0923 \u092f\u0926\u093f \u0915\u094b\u0908 \u092c\u093e\u0939\u0930\u0940 \u092c\u0932 \u0928\u0939\u0940\u0902\u0964<br>\n\u0917\u0924\u093f\u0935\u093f\u0927\u093f 7.2 \u0932\u094b\u0932\u0915 \u091a\u093f\u0924\u094d\u0930 7.20: \u0926\u0940\u0935\u093e\u0930 \u092a\u0930 \u0938\u092b\u0947\u0926 \u0915\u093e\u0917\u091c \u0915\u094d\u0937\u0948\u0924\u093f\u091c \u0930\u0947\u0916\u093e \u0932\u094b\u0932\u0915 \u0915\u0947 \u090a\u092a\u0930 \u091c\u092c \u0928\u0939\u0940\u0902 \u0939\u093f\u0932 \u0930\u0939\u093e\u0964 \u0917\u094b\u0932\u093e \u092c\u093f\u0902\u0926\u0941 P \u0915\u094d\u0937\u0948\u0924\u093f\u091c \u0930\u0947\u0916\u093e \u0938\u094d\u0924\u0930 \u092a\u0930 \u091b\u094b\u0921\u093c\u0928\u093e \u091a\u0930\u092e \u092c\u093f\u0902\u0926\u0941 \u0926\u0947\u0916\u094b \u0915\u0941\u091b \u0926\u094b\u0932\u0928 - \u0932\u0917\u092d\u0917 \u0915\u094d\u0937\u0948\u0924\u093f\u091c \u0930\u0947\u0916\u093e \u0938\u094d\u0924\u0930 \u0924\u0915 \u092a\u0939\u0941\u0901\u091a\u0924\u093e? P \u092a\u0930 \u0938\u094d\u0925\u093f\u0924\u093f\u091c mgh \u0928\u0940\u091a\u0947 \u0938\u0947 \u090a\u0901\u091a\u093e\u0908, Q \u092a\u0930 \u0938\u094d\u0925\u093f\u0924\u093f\u091c \u0936\u0942\u0928\u094d\u092f \u0917\u0924\u093f\u091c, R \u0926\u0942\u0938\u0930\u0940 \u0913\u0930 \u0917\u0924\u093f\u091c \u0936\u0942\u0928\u094d\u092f \u0938\u094d\u0925\u093f\u0924\u093f\u091c \u0935\u093e\u092a\u0938 same \u090a\u0901\u091a\u093e\u0908 - \u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 \u0928\u093f\u092f\u0924\u0964 \u0905\u0938\u0932 \u091c\u093f\u0902\u0926\u0917\u0940 \u092e\u0947\u0902 \u0918\u0930\u094d\u0937\u0923 \u0938\u0939\u093e\u0930\u093e \u0939\u0935\u093e \u092a\u094d\u0930\u0924\u093f\u0930\u094b\u0927 \u090a\u0930\u094d\u091c\u093e \u0939\u093e\u0928\u093f \u0927\u0940\u0930\u0947 \u0930\u0941\u0915\u0924\u093e\u0964<br>\n\u0938\u0902\u0930\u0915\u094d\u0937\u0923 \u0930\u094b\u091c\u092e\u0930\u094d\u0930\u093e \u0915\u0940 \u0938\u092e\u0938\u094d\u092f\u093e\u090f\u0901 \u0939\u0932 \u0915\u0930\u0928\u0947 \u092e\u0947\u0902 \u0909\u092a\u092f\u094b\u0917\u0940 - \u0928\u094d\u092f\u0942\u091f\u0928 \u0928\u093f\u092f\u092e \u0915\u0920\u093f\u0928 \u0938\u0902\u0930\u0915\u094d\u0937\u0923 \u0906\u0938\u093e\u0928 \u0930\u093e\u0938\u094d\u0924\u093e \u0915\u0941\u0932 \u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 \u090a\u0930\u094d\u091c\u093e \u0915\u093e \u0939\u093f\u0938\u093e\u092c \u0905\u0902\u0924\u093f\u092e \u0917\u0924\u093f \u0938\u094d\u0925\u093f\u0924\u093f \u092c\u093f\u0928\u093e \u092c\u0940\u091a \u0915\u0947 \u0915\u0926\u092e - \u091c\u093f\u091c\u094d\u091e\u093e\u0938\u093e \u0915\u0947 \u0927\u093e\u0917\u0947\u0964<br><br>\n\n<b>\u0909\u0926\u093e\u0939\u0930\u0923 7.8 \u092c\u091a\u094d\u091a\u093e \u092b\u093f\u0938\u0932\u0928 \u092a\u091f\u094d\u091f\u0940 \u090a\u0901\u091a\u093e\u0908 h \u0928\u0940\u091a\u0947 \u0935\u0947\u0917? - \u092a\u0947\u091c128:<\/b><br>\n\u090a\u092a\u0930 \u0938\u094d\u0925\u093f\u0924\u093f\u091c mgh, \u0928\u0940\u091a\u0947 \u0917\u0924\u093f\u091c \u00bdmv\u00b2, \u0938\u094d\u0925\u093f\u0924\u093f\u091c \u092a\u0942\u0930\u0940 \u0917\u0924\u093f\u091c \u092e\u0947\u0902 \u092c\u0926\u0932\u0940 \u0918\u0930\u094d\u0937\u0923 \u0928\u0917\u0923\u094d\u092f \u092e\u093e\u0928 \u092c\u0930\u093e\u092c\u0930 \u00bdmv\u00b2=mgh \u2192<b>v=\u221a(2gh)<\/b> - \u0915\u0947\u0935\u0932 \u090a\u0901\u091a\u093e\u0908 h \u092a\u0930 \u0928\u093f\u0930\u094d\u092d\u0930 \u0906\u0915\u093e\u0930 \u0935\u091c\u0928 matter \u0928\u0939\u0940\u0902 - \u0907\u0938\u0932\u093f\u090f \u0938\u094b\u091a\u094b \u0924\u094b \u0905\u0932\u0917 \u0935\u091c\u0928 same \u0938\u094d\u0932\u093e\u0907\u0921 same \u0935\u0947\u0917\u0964<br><br>\n\n<b>\u0909\u0926\u093e\u0939\u0930\u0923 7.9 \u090f\u0938\u094d\u0915\u0947\u092a \u0930\u0948\u0902\u092a \u091a\u093f\u0924\u094d\u0930 7.21 - \u092a\u0947\u091c128:<\/b><br>\n\u091f\u094d\u0930\u0915 10000 kg 72 km\/h =20 m\/s \u092c\u094d\u0930\u0947\u0915 \u092b\u0947\u0932 30\u00b0 \u0922\u0932\u093e\u0928 \u0930\u0947\u0924 \u092c\u0932 50000 N \u0935\u093f\u092a\u0930\u0940\u0924 - \u0928\u094d\u092f\u0942\u0928\u0924\u092e \u0932\u0902\u092c\u093e\u0908? \u092a\u094d\u0930\u093e\u0930\u0902\u092d\u093f\u0915 \u0917\u0924\u093f\u091c=\u00bd\u00d710000\u00d720\u00b2=2000000 J \u092a\u094d\u0930\u093e\u0930\u0902\u092d\u093f\u0915 \u0938\u094d\u0925\u093f\u0924\u093f\u091c0 \u0915\u0941\u0932 \u092a\u094d\u0930\u093e\u0930\u0902\u092d\u093f\u09152000000 J, \u0926\u0942\u0930\u0940 d \u0930\u0948\u0902\u092a \u092a\u0930 \u090a\u0901\u091a\u093e\u0908 \u092c\u0922\u093c\u0924=d\/2 (\u0938\u0902\u0915\u0947\u0924 30\u00b0 \u0922\u0932\u093e\u0928 2 \u092a\u0930 1 \u0932\u0902\u092c\u0935\u0924), \u0905\u0902\u0924\u093f\u092e \u0917\u0924\u093f\u091c0 \u0905\u0902\u0924\u093f\u092e \u0938\u094d\u0925\u093f\u0924\u093f\u091c=mg\u00d7d\/2=10000\u00d710\u00d7d\/2=50000\u00d7d \u0915\u0941\u0932 \u0905\u0902\u0924\u093f\u092e=50000d \u092a\u0930\u093f\u0935\u0930\u094d\u0924\u0928 \u0905\u0902\u0924\u093f\u092e-\u092a\u094d\u0930\u093e\u0930\u0902\u092d\u093f\u0915=50000d-2000000 \u0930\u0947\u0924 \u0915\u093e \u0915\u093e\u0930\u094d\u092f=-50000\u00d7d \u0915\u093e\u0930\u094d\u092f-\u090a\u0930\u094d\u091c\u093e \u092a\u094d\u0930\u092e\u0947\u092f \u0915\u093e\u0930\u094d\u092f=\u092a\u0930\u093f\u0935\u0930\u094d\u0924\u0928 \u2192-50000d=50000d-2000000 \u2192100000d=2000000 \u2192d=20 m \u0928\u094d\u092f\u0942\u0928\u0924\u092e \u0932\u0902\u092c\u093e\u0908\u0964<br><br>\n\n<b>7.6 \u0938\u0930\u0932 \u092e\u0936\u0940\u0928\u0947\u0902 - \u092a\u0947\u091c130-133:<\/b><br>\n\u0930\u094b\u091c\u092e\u0930\u094d\u0930\u093e \u0917\u0941\u0930\u0941\u0924\u094d\u0935\u093e\u0915\u0930\u094d\u0937\u0923 \u0905\u0928\u094d\u092f \u092c\u0932 \u092d\u093e\u0930\u0940 \u0935\u0938\u094d\u0924\u0941 \u0909\u0920\u093e\u0928\u093e \u091a\u0932\u093e\u0928\u093e - \u0915\u0941\u0932 \u0915\u093e\u0930\u094d\u092f \u0915\u092e \u0928\u0939\u0940\u0902 \u0915\u093f\u092f\u093e \u091c\u093e \u0938\u0915\u0924\u093e \u0932\u0947\u0915\u093f\u0928 \u0906\u0938\u093e\u0928 \u092c\u0932 \u0915\u093e \u092a\u0930\u093f\u092e\u093e\u0923 \u0926\u093f\u0936\u093e \u092c\u0926\u0932\u0915\u0930 - \u092f\u0941\u0915\u094d\u0924\u093f \u0938\u0930\u0932 \u092e\u0936\u0940\u0928\u0947\u0902\u0964<br>\n\u0924\u0940\u0928 \u0938\u0930\u0932 \u092e\u0936\u0940\u0928\u0947\u0902 - \u0918\u093f\u0930\u0928\u0940, \u0906\u0928\u0924 \u0924\u0932, \u0909\u0924\u094d\u0924\u094b\u0932\u0915 - \u0939\u092e \u091c\u094b \u092c\u0932 \u0932\u0917\u093e\u0924\u0947 \u092a\u094d\u0930\u092f\u093e\u0938, \u091c\u094b \u092c\u0932 \u0939\u0930\u093e\u0928\u093e \u092d\u093e\u0930\u0964<br>\n<b>\u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 \u0932\u093e\u092d = \u092d\u093e\u0930\/\u092a\u094d\u0930\u092f\u093e\u0938 \u0938\u092e\u0940\u0915\u0930\u0923 7.12<\/b><br><br>\n\n<b>7.6.1 \u0918\u093f\u0930\u0928\u0940 - \u091a\u093f\u0924\u094d\u0930 7.23 \u091a\u093f\u0924\u094d\u0930 7.24 \u091a\u093f\u0924\u094d\u0930 7.25 - \u092a\u0947\u091c130:<\/b><br>\n\u092a\u0939\u093f\u092f\u093e \u0916\u093e\u0901\u091a\u093e \u0930\u0938\u094d\u0938\u0940 \u0928\u093f\u0930\u094d\u0926\u0947\u0936 \u091a\u093f\u0924\u094d\u0930 7.23 \u0938\u094d\u0925\u093f\u0930 \u0918\u093f\u0930\u0928\u0940 \u092a\u0930\u093f\u092e\u093e\u0923 \u0915\u092e \u0928\u0939\u0940\u0902 \u0915\u0947\u0935\u0932 \u0926\u093f\u0936\u093e \u092c\u0926\u0932\u0924\u0940 - \u0928\u0940\u091a\u0947 \u0916\u0940\u0902\u091a\u0928\u093e \u0906\u0938\u093e\u0928 \u0938\u0940\u0927\u0947 \u090a\u092a\u0930 \u0909\u0920\u093e\u0928\u0947 \u0938\u0947 \u091a\u093f\u0924\u094d\u0930 7.24a \u0938\u0940\u0927\u0947 \u091a\u093f\u0924\u094d\u0930 7.24b \u0918\u093f\u0930\u0928\u0940 \u0909\u092a\u092f\u094b\u0917 \u0938\u0941\u0935\u093f\u0927\u093e \u0926\u093f\u0936\u093e \u092a\u094d\u0930\u092f\u093e\u0938 - \u092a\u094d\u0930\u092f\u093e\u0938 \u092d\u093e\u0930 \u092c\u0930\u093e\u092c\u0930 \u092a\u0930\u093f\u092e\u093e\u0923 \u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 \u0932\u093e\u092d \u0938\u094d\u0925\u093f\u0930 \u0918\u093f\u0930\u0928\u0940 1 \u0938\u092e\u0940\u0915\u0930\u0923 7.12\u0964<br>\n\u091a\u0932 \u0918\u093f\u0930\u0928\u0940 \u092a\u094d\u0930\u0923\u093e\u0932\u0940 \u091a\u093f\u0924\u094d\u0930 7.25 \u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 \u0932\u093e\u092d >1 \u092d\u093e\u0930\u0940 \u0915\u092e \u092a\u094d\u0930\u092f\u093e\u0938 \u092e\u0947\u0902 \u0909\u0920\u093e\u0928\u093e - \u092d\u093e\u0930 \u091a\u0932 \u0918\u093f\u0930\u0928\u0940 \u0938\u0947 \u091c\u0941\u0921\u093c\u093e \u0930\u0938\u094d\u0938\u0940 \u090f\u0915 \u0938\u093f\u0930\u093e \u0938\u094d\u0925\u093f\u0930 \u0926\u0942\u0938\u0930\u093e \u092e\u0941\u0915\u094d\u0924 \u092a\u094d\u0930\u092f\u093e\u0938 - \u0935\u094d\u092f\u093e\u092a\u0915 \u0932\u093f\u092b\u094d\u091f \u0915\u094d\u0930\u0947\u0928\u0964<br>\n\u0936\u0915\u094d\u0924\u093f \u0935\u093e\u091f \u0928\u093e\u092e \u091c\u0947\u092e\u094d\u0938 \u0935\u093e\u091f \u092d\u093e\u092a \u0907\u0902\u091c\u0928 \u0906\u0935\u093f\u0937\u094d\u0915\u093e\u0930 \u0918\u0942\u0930\u094d\u0923\u0928 \u0917\u0924\u093f \u092a\u0939\u093f\u090f \u091a\u0932\u093e\u0928\u093e - \u0935\u0948\u091c\u094d\u091e\u093e\u0928\u093f\u0915 \u0938\u0947 \u092e\u093f\u0932\u094b \u092a\u0947\u091c130\u0964<br><br>\n\n<b>7.6.2 \u0906\u0928\u0924 \u0924\u0932 - \u091a\u093f\u0924\u094d\u0930 7.28 \u091a\u093f\u0924\u094d\u0930 7.29 - \u092a\u0947\u091c132-133:<\/b><br>\n\u092d\u093e\u0930\u0940 \u092d\u093e\u0930 \u090a\u0901\u091a\u093e \u0928\u0940\u091a\u0947 \u0938\u094d\u0924\u0930 - \u091a\u093f\u0924\u094d\u0930 7.28a \u0932\u0902\u092c\u0935\u0924 \u090a\u0901\u091a\u093e\u0908 h \u092c\u0932 F' \u092a\u094d\u0930\u092f\u093e\u0938 \u091b\u094b\u091f\u0940 \u0926\u0942\u0930\u0940 \u092c\u0921\u093c\u093e \u092c\u0932 \u091a\u093f\u0924\u094d\u0930 7.28b \u0906\u0928\u0924 \u0932\u0902\u092c\u093e\u0908 L \u092c\u0921\u093c\u0940 \u0926\u0942\u0930\u0940 \u091b\u094b\u091f\u093e \u092c\u0932 \u091a\u093f\u0924\u094d\u0930 7.28c \u092c\u0921\u093c\u0940 \u0932\u0902\u092c\u093e\u0908 \u0915\u092e \u0922\u093e\u0932 \u091b\u094b\u091f\u093e \u092a\u094d\u0930\u092f\u093e\u0938\u0964<br>\n\u0926\u094d\u0930\u0935\u094d\u092f\u092e\u093e\u0928 m \u092d\u093e\u0930 \u0935\u091c\u0928 mg \u092a\u094d\u0930\u092f\u093e\u0938 F' \u090a\u0901\u091a\u093e\u0908 h \u0932\u0902\u092c\u093e\u0908 L \u0928\u093f\u092f\u0924 \u0917\u0924\u093f \u0915\u093e\u0930\u094d\u092f \u0906\u092a=F'\u00d7L \u0938\u094d\u0925\u093f\u0924\u093f\u091c \u092c\u0922\u093c\u0924=mgh \u0915\u093e\u0930\u094d\u092f-\u090a\u0930\u094d\u091c\u093e \u092a\u094d\u0930\u092e\u0947\u092f \u0918\u0930\u094d\u0937\u0923 \u0928\u0917\u0923\u094d\u092f F'\u00d7L=mgh \u2192mg\/F'=L\/h \u2192<b>\u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 \u0932\u093e\u092d = \u092d\u093e\u0930\/\u092a\u094d\u0930\u092f\u093e\u0938 = mg\/F' = L\/h \u0938\u092e\u0940\u0915\u0930\u0923 7.13<\/b> - L \u092c\u0921\u093c\u093e h \u0938\u0947 \u092c\u0932 F' mg \u0938\u0947 \u0915\u092e \u0932\u093e\u092d >1 L \u092c\u0922\u093c\u093e \u0915\u092e \u0922\u093e\u0932 \u092a\u094d\u0930\u092f\u093e\u0938 F' \u0918\u091f\u093e\u0964 \u0915\u093f\u092f\u093e \u0917\u092f\u093e \u0915\u093e\u0930\u094d\u092f \u092c\u0932 \u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928 \u0917\u0941\u0923\u0928\u092b\u0932 same \u0938\u092d\u0940 \u092e\u093e\u092e\u0932\u094b\u0902 \u092e\u0947\u0902 \u092c\u0932 \u0918\u091f\u093e \u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928 \u092c\u0922\u093c\u093e \u0915\u093e\u0930\u094d\u092f \u0928\u093f\u092f\u0924 \u0928\u094b\u091f \u092a\u0947\u091c132\u0964<br>\n\u0909\u0926\u093e\u0939\u0930\u0923 7.12 \u0935\u094d\u092f\u0915\u094d\u0924\u093f \u0930\u0948\u0902\u092a \u0938\u0940\u0922\u093c\u0940 30 cm \u090a\u0901\u091a\u0940 \u091a\u094c\u0921\u093c\u093e\u0908 40 cm \u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 \u0932\u093e\u092d? \u0932\u0902\u092c\u093e\u0908 AC 50 cm \u0938\u092e\u0915\u094b\u0923 \u0924\u094d\u0930\u093f\u092d\u0941\u091c 3-4-5 \u2192MA=L\/h=50\/30=1.67<br>\nQ9 \u0938\u094b\u091a\u094b \u0914\u0930 \u092c\u0924\u093e\u0913: \u092a\u0939\u093e\u0921\u093c\u094b\u0902 \u092e\u0947\u0902 \u0938\u0921\u093c\u0915\u0947\u0902 \u0918\u0941\u092e\u093e\u0935\u0926\u093e\u0930 \u0939\u0932\u094d\u0915\u0940 \u0922\u093e\u0932 \u0938\u0940\u0927\u0940 \u090a\u092a\u0930 \u0915\u094d\u092f\u094b\u0902 \u0928\u0939\u0940\u0902 \u091a\u093f\u0924\u094d\u0930 4.26? \u0915\u094d\u092f\u094b\u0902\u0915\u093f \u0939\u0932\u094d\u0915\u0940 \u0922\u093e\u0932 L \u092c\u0922\u093c\u093e \u092a\u094d\u0930\u092f\u093e\u0938 \u0915\u092e \u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 \u0932\u093e\u092d \u092c\u0922\u093c\u093e\u0964<br>\nQ10 \u090a\u0901\u091a\u0940 \u092e\u0902\u091c\u093f\u0932 \u0906\u0928\u0924 \u0938\u0940\u0922\u093c\u0940 \u0938\u0940\u0927\u0940 \u0938\u0940\u0922\u093c\u0940 \u0938\u0947 \u0906\u0938\u093e\u0928 \u0915\u094d\u092f\u094b\u0902 \u091a\u093f\u0924\u094d\u0930 7.30? same \u0915\u093e\u0930\u0923 \u0906\u0928\u0924 \u0924\u0932 MA>1 \u092c\u0932 \u0915\u092e\u0964<br><br>\n\n<b>7.6.3 \u0909\u0924\u094d\u0924\u094b\u0932\u0915 - \u091a\u093f\u0924\u094d\u0930 7.31 \u091a\u093f\u0924\u094d\u0930 7.32 \u0924\u093e\u0932\u093f\u0915\u093e 7.2 \u091a\u093f\u0924\u094d\u0930 7.33 \u091a\u093f\u0924\u094d\u0930 7.35 - \u092a\u0947\u091c133-135:<\/b><br>\n\u0917\u0924\u093f\u0935\u093f\u0927\u093f 7.4 \u0938\u094d\u0915\u0947\u0932 \u092a\u0947\u0902\u0938\u093f\u0932 2-3 \u0930\u092c\u0921\u093c \u0938\u094d\u091f\u0947\u092a\u0932\u0930 - \u0938\u094d\u0915\u0947\u0932 \u092a\u0947\u0902\u0938\u093f\u0932 \u092a\u0930 \u090f\u0915 \u0938\u093f\u0930\u0947 \u0915\u0947 \u092a\u093e\u0938 \u0938\u094d\u091f\u0947\u092a\u0932\u0930 \u0926\u0942\u0938\u0930\u0947 \u0938\u093f\u0930\u0947 \u092a\u0930 \u0930\u092c\u0921\u093c - \u092d\u093e\u0930\u0940 \u0938\u094d\u091f\u0947\u092a\u0932\u0930 \u0939\u0932\u094d\u0915\u0940 \u0930\u092c\u0921\u093c \u0938\u0947 \u0909\u0920\u093e - \u0938\u094d\u0915\u0947\u0932 \u0938\u0930\u0932 \u092e\u0936\u0940\u0928 \u0909\u0924\u094d\u0924\u094b\u0932\u0915 \u0915\u0920\u094b\u0930 \u091b\u0921\u093c \u0918\u0942\u092e\u0924\u0940 \u0938\u094d\u0925\u093f\u0930 \u092c\u093f\u0902\u0926\u0941 \u0938\u0902\u092a\u0930\u094d\u0915 \u0938\u094d\u0915\u0947\u0932 \u092a\u0947\u0902\u0938\u093f\u0932\u0964<br>\n\u0924\u0940\u0928 \u092e\u0941\u0916\u094d\u092f \u092d\u093e\u0917 \u091a\u093f\u0924\u094d\u0930 7.32: \u0906\u0932\u0902\u092c \u0938\u094d\u0925\u093f\u0930 \u092c\u093f\u0902\u0926\u0941 \u0918\u0942\u092e\u0928\u093e, \u092d\u093e\u0930 \u0939\u0930\u093e\u0928\u0947 \u0935\u093e\u0932\u093e \u092c\u0932, \u092a\u094d\u0930\u092f\u093e\u0938 \u0932\u0917\u093e\u092f\u093e \u0917\u092f\u093e \u092c\u0932\u0964 \u0926\u0942\u0930\u0940 \u092d\u093e\u0930 \u0906\u0932\u0902\u092c \u092d\u093e\u0930 \u092d\u0941\u091c\u093e, \u092a\u094d\u0930\u092f\u093e\u0938 \u0906\u0932\u0902\u092c \u092a\u094d\u0930\u092f\u093e\u0938 \u092d\u0941\u091c\u093e\u0964<br>\n\u091b\u094b\u091f\u093e \u092c\u0932 F1 \u092c\u0921\u093c\u093e \u0926\u0942\u0930\u0940 d1 \u0926\u0942\u0938\u0930\u0947 \u0938\u093f\u0930\u0947 \u092a\u0930 \u092c\u0921\u093c\u093e \u092c\u0932 F2 \u092d\u093e\u0930\u0940 \u0935\u0938\u094d\u0924\u0941 \u091b\u094b\u091f\u0940 \u0926\u0942\u0930\u0940 d2 \u0915\u093e\u0930\u094d\u092f \u090f\u0915 \u0938\u093f\u0930\u0947 \u0938\u0947 \u0926\u0942\u0938\u0930\u0947 \u0938\u093f\u0930\u0947 \u0938\u094d\u0925\u093e\u0928\u093e\u0902\u0924\u0930\u093f\u0924 \u0938\u092e\u0940\u0915\u0930\u0923 7.1 F1\u00d7d1=F2\u00d7d2 \u0938\u092e\u0940\u0915\u0930\u0923 7.14 \u092a\u094d\u0930\u092f\u093e\u0938 \u092d\u0941\u091c\u093e \u092c\u0922\u093c\u093e \u0909\u0924\u094d\u0924\u094b\u0932\u0915 \u092c\u0921\u093c\u093e \u092c\u0932 F2 \u092d\u093e\u0930 \u092a\u094d\u0930\u092f\u093e\u0938 F1 \u0924\u0941\u0932\u0928\u093e\u0964 \u0928\u094b\u091f \u0909\u0924\u094d\u0924\u094b\u0932\u0915 \u092c\u0932 \u0915\u092e \u0915\u0930\u0924\u093e \u0915\u0941\u0932 \u0915\u093e\u0930\u094d\u092f \u0928\u0939\u0940\u0902\u0964<br>\n\u0917\u0924\u093f\u0935\u093f\u0927\u093f 7.5 \u0924\u0930\u093e\u091c\u0942 \u0938\u094d\u0915\u0947\u0932 \u0927\u093e\u0917\u093e \u0915\u093e\u0917\u091c \u0915\u092a \u0938\u093f\u0915\u094d\u0915\u0947 \u0935\u091c\u0928 - \u0924\u0930\u093e\u091c\u0942 \u0909\u0924\u094d\u0924\u094b\u0932\u0915\u0964<br>\n\u0924\u093e\u0932\u093f\u0915\u093e 7.2 \u0909\u0924\u094d\u0924\u094b\u0932\u0915 \u0935\u0930\u094d\u0917: \u0935\u0930\u094d\u0917 I \u0906\u0932\u0902\u092c \u092c\u0940\u091a \u092e\u0947\u0902 \u092d\u093e\u0930 \u092a\u094d\u0930\u092f\u093e\u0938 - \u091a\u093f\u092e\u091f\u093e \u0915\u0948\u0902\u091a\u0940 \u0938\u092c\u094d\u092c\u0932 \u092a\u094d\u0932\u093e\u0938 \u0924\u0930\u093e\u091c\u0942 \u091d\u0942\u0932\u093e, \u0935\u0930\u094d\u0917 II \u092d\u093e\u0930 \u092c\u0940\u091a \u092e\u0947\u0902 \u0906\u0932\u0902\u092c \u092a\u094d\u0930\u092f\u093e\u0938 - \u0928\u0940\u0902\u092c\u0942 \u0928\u093f\u091a\u094b\u0921\u093c \u0920\u0947\u0932\u093e \u092c\u094b\u0924\u0932 \u0916\u094b\u0932\u0928\u0947 \u0935\u093e\u0932\u093e, \u0935\u0930\u094d\u0917 III \u092a\u094d\u0930\u092f\u093e\u0938 \u092c\u0940\u091a \u092e\u0947\u0902 \u0906\u0932\u0902\u092c \u092d\u093e\u0930 - \u091a\u093f\u092e\u091f\u0940 \u091a\u093f\u092e\u091f\u093e \u091d\u093e\u0921\u093c\u0942 \u0939\u0925\u094c\u0921\u093c\u093e \u092a\u0924\u0935\u093e\u0930\u0964<br>\n\u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 \u090a\u0930\u094d\u091c\u093e \u0938\u0902\u0930\u0915\u094d\u0937\u0923 \u0932\u093e\u0917\u0942 \u0939\u092e \u091c\u094b \u0915\u093e\u0930\u094d\u092f \u0932\u0917\u093e\u0924\u0947 \u092c\u0930\u093e\u092c\u0930 \u0909\u092a\u092f\u094b\u0917\u0940 \u0915\u093e\u0930\u094d\u092f \u092d\u093e\u0930 \u0918\u0930\u094d\u0937\u0923 \u0928\u0917\u0923\u094d\u092f \u092e\u0936\u0940\u0928\u0947\u0902 \u090a\u0930\u094d\u091c\u093e \u0928\u0939\u0940\u0902 \u092c\u0928\u093e\u0924\u0940 \u0915\u0947\u0935\u0932 \u0905\u0927\u093f\u0915 \u092a\u094d\u0930\u092d\u093e\u0935\u0940 \u0909\u092a\u092f\u094b\u0917\u0964<br>\nQ11 \u0922\u0915\u094d\u0915\u0928 \u0916\u094b\u0932\u0928\u093e \u091a\u092e\u094d\u092e\u091a \u0938\u0947 \u0906\u0938\u093e\u0928 \u0915\u094d\u092f\u094b\u0902 \u091a\u093f\u0924\u094d\u0930 7.35? \u091a\u092e\u094d\u092e\u091a \u0909\u0924\u094d\u0924\u094b\u0932\u0915 \u0906\u0932\u0902\u092c \u0915\u093f\u0928\u093e\u0930\u093e \u092a\u094d\u0930\u092f\u093e\u0938 \u092d\u0941\u091c\u093e \u092c\u0921\u093c\u0940 \u092d\u093e\u0930 \u092d\u0941\u091c\u093e \u091b\u094b\u091f\u0940 \u092c\u0932 \u092c\u0922\u093c\u093e\u0964<br>\nQ12 \u0915\u0948\u0902\u091a\u0940 \u092e\u0947\u0902 \u0935\u0938\u094d\u0924\u0941 \u0906\u0932\u0902\u092c \u0915\u0947 \u092a\u093e\u0938 \u0927\u0915\u0947\u0932\u0928\u093e \u0915\u0920\u093f\u0928 \u0935\u0938\u094d\u0924\u0941 \u0915\u093e\u091f\u0928\u093e? \u092a\u093e\u0938 \u092d\u093e\u0930 \u092d\u0941\u091c\u093e \u091b\u094b\u091f\u0940 \u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 \u0932\u093e\u092d \u091c\u094d\u092f\u093e\u0926\u093e \u092c\u0932\u0964<br>\nQ13 \u0938\u0924\u0924 \u092e\u0936\u0940\u0928\u0947\u0902 \u092a\u0939\u093f\u090f \u0935\u091c\u0928 \u091a\u0941\u0902\u092c\u0915 \u092a\u094d\u0930\u0938\u094d\u0924\u093e\u0935\u093f\u0924 \u0915\u094b\u0908 \u0915\u093e\u092e \u0928\u0939\u0940\u0902 \u0915\u094d\u092f\u094b\u0902 \u0905\u0938\u0932\u0940 \u092e\u0936\u0940\u0928\u0947\u0902 \u0927\u0940\u0930\u0947 \u0930\u0941\u0915\u0924\u0940? \u0918\u0930\u094d\u0937\u0923 \u0939\u0935\u093e \u092a\u094d\u0930\u0924\u093f\u0930\u094b\u0927 \u090a\u0930\u094d\u091c\u093e \u0939\u093e\u0928\u093f \u090a\u0937\u094d\u092e\u093e \u0927\u094d\u0935\u0928\u093f \u0938\u0902\u0930\u0915\u094d\u0937\u0923 \u090a\u0930\u094d\u091c\u093e \u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 \u0938\u0902\u0930\u0915\u094d\u0937\u093f\u0924 \u0928\u0939\u0940\u0902 \u0908\u0902\u0927\u0928 \u092c\u093f\u0928\u093e\u0964<br><br>\n\n<b>\u0935\u093f\u091c\u094d\u091e\u093e\u0928 \u0938\u092e\u093e\u091c \u091c\u094b\u0921\u093c \u091a\u093f\u0924\u094d\u0930 7.36 \u092a\u0928\u091a\u0915\u094d\u0915\u0940 \u0918\u0930\u093e\u091f \u092a\u0902\u091a\u0915\u094d\u0915\u0940 \u0939\u093f\u092e\u093e\u0932\u092f \u0915\u094d\u0937\u0947\u0924\u094d\u0930 \u092a\u093e\u0928\u0940 \u0928\u0940\u091a\u0947 \u0938\u094d\u0925\u093f\u0924\u093f\u091c\u2192\u0917\u0924\u093f\u091c \u092a\u0939\u093f\u092f\u093e B \u0918\u0942\u0930\u094d\u0923\u0928 \u092a\u0940\u0938\u0928\u0947 \u0935\u093e\u0932\u093e \u092a\u0924\u094d\u0925\u0930 \u090a\u092a\u0930 C \u0918\u0941\u092e\u093e\u0924\u093e - 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\u0936\u0942\u0928\u094d\u092f F=0 s=0 \u0932\u0902\u092c\u0935\u0924, \u0927\u0928\u093e\u0924\u094d\u092e\u0915 same \u0926\u093f\u0936\u093e \u0935\u094d\u0939\u0940\u0932\u091a\u0947\u092f\u0930, \u090b\u0923\u093e\u0924\u094d\u092e\u0915 \u0935\u093f\u092a\u0930\u0940\u0924 \u0917\u094b\u0932\u0915\u0940\u092a\u0930 -30J 200N\u00d7-0.15<br>\n\u0915\u093e\u0930\u094d\u092f-\u090a\u0930\u094d\u091c\u093e \u092a\u094d\u0930\u092e\u0947\u092f \u0915\u093e\u0930\u094d\u092f=\u090a\u0930\u094d\u091c\u093e \u092a\u0930\u093f\u0935\u0930\u094d\u0924\u0928 \u0938\u092e\u0940\u0915\u0930\u0923 7.3 - \u090a\u0930\u094d\u091c\u093e \u0915\u093e\u0930\u094d\u092f \u0915\u0930\u0928\u0947 \u0915\u0940 \u0915\u094d\u0937\u092e\u0924\u093e - \u0938\u094d\u0925\u093e\u0928\u093e\u0902\u0924\u0930\u0923 \u090a\u0937\u094d\u092e\u093e \u0935\u093f\u0915\u093f\u0930\u0923 \u092c\u093f\u091c\u0932\u0940 \u0927\u094d\u0935\u0928\u093f \u0928\u093e\u092d\u093f\u0915\u0940\u092f<br>\n\u0930\u0942\u092a \u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 \u090a\u0937\u094d\u092e\u0940\u092f \u092a\u094d\u0930\u0915\u093e\u0936 \u0927\u094d\u0935\u0928\u093f \u0935\u093f\u0926\u094d\u092f\u0941\u0924 \u0928\u093e\u092d\u093f\u0915\u0940\u092f \u0930\u093e\u0938\u093e\u092f\u0928\u093f\u0915 \u091a\u093f\u0924\u094d\u0930 7.10 - \u0930\u093e\u0938\u093e\u092f\u0928\u093f\u0915 \u092d\u094b\u091c\u0928\u2192\u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 \u092e\u093e\u0902\u0938\u092a\u0947\u0936\u093f\u092f\u093e\u0901, \u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915\u2192\u0927\u094d\u0935\u0928\u093f \u0918\u0902\u091f\u0940, \u0935\u093f\u0926\u094d\u092f\u0941\u0924\u2192\u092a\u094d\u0930\u0915\u093e\u0936 \u092c\u0932\u094d\u092c \u090a\u0937\u094d\u092e\u0940\u092f \u0939\u0940\u091f\u0930<br>\n\u0917\u0924\u093f\u091c K=\u00bdmv\u00b2 \u0938\u092e\u0940\u0915\u0930\u0923 7.6 v\u00b2=u\u00b2+2as W=ma\u00d7s=\u00bdm(v\u00b2-u\u00b2) - \u0926\u094b\u0917\u0941\u0928\u093e \u0935\u0947\u0917 4\u00d7 \u0917\u0924\u093f\u091c - \u0917\u0947\u0902\u0926 0.2kg 43m\/s 184.9J - \u091c\u0947\u091f 15000kg 367500N 100m v=70m\/s 252km\/h - m 4m same K \u0935\u0947\u0917 \u0905\u0928\u0941\u092a\u093e\u0924 2:1 - \u0928\u093f\u092f\u0924 \u0935\u0947\u0917 K same<br>\n\u0938\u094d\u0925\u093f\u0924\u093f\u091c \u091c\u092e\u093e \u0935\u093f\u0930\u0942\u092a\u0923 \u0938\u093e\u092a\u0947\u0915\u094d\u0937 \u0938\u094d\u0925\u093f\u0924\u093f - \u0938\u094d\u092a\u094d\u0930\u093f\u0902\u0917 \u091a\u093f\u0924\u094d\u0930 7.14, \u091a\u0941\u0902\u092c\u0915 \u091a\u093f\u0924\u094d\u0930 7.15, \u092a\u0943\u0925\u094d\u0935\u0940-\u0917\u0947\u0902\u0926 \u091a\u093f\u0924\u094d\u0930 7.16 - U=mgh \u0938\u092e\u0940\u0915\u0930\u0923 7.8 W=mgh - \u0917\u0947\u0902\u0926 0.2kg 10m 20J - \u0915\u094d\u0937\u0948\u0924\u093f\u091c \u0928\u093f\u092f\u0924 \u0915\u094b\u0908 \u092a\u0930\u093f\u0935\u0930\u094d\u0924\u0928 \u0928\u0939\u0940\u0902 \u0932\u0902\u092c\u0935\u0924 \u0909\u0920\u093e\u0928\u0947 \u092a\u0930 \u092c\u0922\u093c\u0940<br>\n\u0938\u0902\u0930\u0915\u094d\u0937\u0923 \u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915=K+U \u0928\u093f\u092f\u0924 \u092f\u0926\u093f \u092c\u093e\u0939\u0930\u0940 \u0928\u0939\u0940\u0902 - \u092e\u0941\u0915\u094d\u0924 \u0917\u093f\u0930\u0928\u093e mgh \u0928\u093f\u092f\u0924, \u0932\u094b\u0932\u0915 \u091a\u093f\u0924\u094d\u0930 7.20 P \u0938\u094d\u0925\u093f\u0924\u093f\u091c mgh Q \u0917\u0924\u093f\u091c R \u0938\u094d\u0925\u093f\u0924\u093f\u091c same \u090a\u0901\u091a\u093e\u0908 \u0918\u0930\u094d\u0937\u0923 \u0939\u093e\u0928\u093f \u0930\u0941\u0915\u0928\u093e<br>\n\u092c\u091a\u094d\u091a\u093e \u0938\u094d\u0932\u093e\u0907\u0921 v=\u221a(2gh) \u0935\u091c\u0928 \u0906\u0915\u093e\u0930 matter \u0928\u0939\u0940\u0902, \u090f\u0938\u094d\u0915\u0947\u092a \u0930\u0948\u0902\u092a 20m - 10000kg 20m\/s 2000000J \u0930\u0947\u0924 50000N d=20m<br>\n\u0938\u0930\u0932 \u092e\u0936\u0940\u0928\u0947\u0902 \u092a\u094d\u0930\u092f\u093e\u0938 \u092d\u093e\u0930 MA=\u092d\u093e\u0930\/\u092a\u094d\u0930\u092f\u093e\u0938 \u0938\u092e\u0940\u0915\u0930\u0923 7.12 - \u0918\u093f\u0930\u0928\u0940 \u091a\u093f\u0924\u094d\u0930 7.23 \u0938\u094d\u0925\u093f\u0930 MA1 \u0926\u093f\u0936\u093e \u092c\u0926\u0932 \u091a\u0932 >1 \u0932\u093f\u092b\u094d\u091f \u0915\u094d\u0930\u0947\u0928, \u0906\u0928\u0924 \u0924\u0932 MA=L\/h \u0938\u092e\u0940\u0915\u0930\u0923 7.13 L>h F'<mg \u0932\u093e\u092d>1 \u0930\u0948\u0902\u092a 30cm 40cm 50cm MA1.67 \u092a\u0939\u093e\u0921\u093c \u0938\u0921\u093c\u0915\u0947\u0902 \u0939\u0932\u094d\u0915\u0940 \u0922\u093e\u0932 L \u092c\u0922\u093c\u093e \u092a\u094d\u0930\u092f\u093e\u0938 \u0918\u091f\u093e, \u0909\u0924\u094d\u0924\u094b\u0932\u0915 F1d1=F2d2 \u0938\u092e\u0940\u0915\u0930\u0923 7.14 \u0906\u0932\u0902\u092c \u092d\u093e\u0930 \u092a\u094d\u0930\u092f\u093e\u0938 \u092d\u093e\u0930 \u092d\u0941\u091c\u093e \u092a\u094d\u0930\u092f\u093e\u0938 \u092d\u0941\u091c\u093e \u0935\u0930\u094d\u0917 I \u0906\u0932\u0902\u092c \u092c\u0940\u091a \u0915\u0948\u0902\u091a\u0940 \u091d\u0942\u0932\u093e II \u092d\u093e\u0930 \u092c\u0940\u091a \u0920\u0947\u0932\u093e III \u092a\u094d\u0930\u092f\u093e\u0938 \u092c\u0940\u091a \u091a\u093f\u092e\u091f\u0940 \u091d\u093e\u0921\u093c\u0942 - \u091a\u092e\u094d\u092e\u091a \u0922\u0915\u094d\u0915\u0928 \u0909\u0924\u094d\u0924\u094b\u0932\u0915, \u0938\u0924\u0924 \u092e\u0936\u0940\u0928 \u092b\u0947\u0932 \u0918\u0930\u094d\u0937\u0923<br>\n\u092a\u0928\u091a\u0915\u094d\u0915\u0940 \u0918\u0930\u093e\u091f \u092a\u0902\u091a\u0915\u094d\u0915\u0940 \u0938\u094d\u0925\u093f\u0924\u093f\u091c\u2192\u0917\u0924\u093f\u091c\u2192\u092a\u0940\u0938\u0928\u093e \u092c\u093e\u0901\u0927 \u092c\u093f\u091c\u0932\u0940<br>\n\u0905\u0917\u0932\u093e \u092d\u093e\u0917 \u092a\u0930\u093f\u092d\u093e\u0937\u093e \u0938\u093f\u0926\u094d\u0927\u093e\u0902\u0924 \u0938\u0942\u0924\u094d\u0930 \u092c\u0928\u093e\u090a\u0901 \u0938\u0930?\n<\/div>\n\n<\/div><\/div>\n<\/div>\n\n<div style=\"background:#bf360c;padding:12px;display:flex;justify-content:space-between;align-items:center;\">\n<button type=\"button\" id=\"c7hp\" style=\"background:#ffcc00;color:#000;border:3px solid #fff;border-radius:30px;padding:10px 22px;font-weight:bold;cursor:pointer;min-width:100px;\">&larr; \u092a\u0940\u091b\u0947<\/button>\n<span id=\"c7hi\" style=\"background:#fff;color:#bf360c;padding:8px 20px;border-radius:20px;font-weight:bold;\">1 \/ 5<\/span>\n<button type=\"button\" id=\"c7hn\" style=\"background:#00e676;color:#000;border:3px solid #fff;border-radius:30px;padding:10px 22px;font-weight:bold;cursor:pointer;min-width:100px;\">\u0906\u0917\u0947 &rarr;<\/button>\n<\/div>\n<\/div>\n\n<script>\n(function(){\nvar c=1,t=5;\nfunction s(n){\nfor(var i=1;i<=t;i++){\nvar el=document.getElementById('c7h-'+i);\nif(el)el.style.display=(i===n?'block':'none');\n}\ndocument.getElementById('c7hi').textContent=n+' \/ '+t;\nc=n;\n}\ndocument.getElementById('c7hn').onclick=function(){var n=c+1;if(n>t)n=1;s(n);};\ndocument.getElementById('c7hp').onclick=function(){var n=c-1;if(n<1)n=t;s(n);};\n})();\n<\/script><\/div><\/div><\/div><\/div><div id=\"pg-838-1\"  class=\"panel-grid panel-no-style\" ><div id=\"pgc-838-1-0\"  class=\"panel-grid-cell\" ><div id=\"panel-838-1-0-0\" class=\"widget_text so-panel widget widget_custom_html panel-first-child panel-last-child\" data-index=\"1\" ><div class=\"textwidget custom-html-widget\"><div id=\"CH7-DEF-HI\" style=\"max-width:860px;margin:12px auto;border:4px solid #bf360c;border-radius:14px;background:#fbe9e7;font-family:'Noto Sans Devanagari',Arial,sans-serif;overflow:hidden;\">\n<div style=\"background:#bf360c;padding:10px;text-align:center;\"><span style=\"background:#fff;color:#bf360c;padding:7px 20px;border-radius:20px;font-weight:bold;font-size:14px;\">\u0905\u0927\u094d\u092f\u093e\u092f 7 - \u092a\u0930\u093f\u092d\u093e\u0937\u093e \u0938\u093f\u0926\u094d\u0927\u093e\u0902\u0924 \u0938\u0942\u0924\u094d\u0930 - PDF \u0932\u093e\u0907\u0928 \u092a\u0947\u091c \u0928\u0902\u092c\u0930 \u0938\u0939\u093f\u0924<\/span><\/div>\n\n<div style=\"padding:10px 12px;\">\n<div id=\"d7h-1\" style=\"display:block;\"><div style=\"background:#b71c1c;color:#fff;padding:6px 14px;border-radius:20px;font-size:13px;font-weight:bold;display:inline-block;margin-bottom:8px;\">\ud83d\udd34 \u092d\u093e\u0917 1\/5 - \u0915\u093e\u0930\u094d\u092f \u0915\u0940 \u092a\u0930\u093f\u092d\u093e\u0937\u093e - \u092a\u0947\u091c 117-119<\/div><div style=\"background:#fff;border:1.5px solid #bf360c;border-radius:10px;padding:12px;font-size:14px;line-height:1.9;height:580px;overflow-y:auto;\">\n\n<div style=\"background:#ffebee;border-left:4px solid #b71c1c;padding:8px 10px;font-weight:bold;\">\u092a\u0947\u091c 117 Eq 7.1 - PDF \u0932\u093e\u0907\u0928:<\/div>\n<b>\u092a\u0930\u093f\u092d\u093e\u0937\u093e:<\/b> \"work done on an object by a constant force = force applied \u00d7 displacement in the direction of the force (7.1)\"<br>\n<b>\u0939\u093f\u0902\u0926\u0940:<\/b> \u0928\u093f\u092f\u0924 \u092c\u0932 \u0926\u094d\u0935\u093e\u0930\u093e \u0935\u0938\u094d\u0924\u0941 \u092a\u0930 \u0915\u093f\u092f\u093e \u0917\u092f\u093e \u0915\u093e\u0930\u094d\u092f = \u0932\u0917\u093e\u092f\u093e \u0917\u092f\u093e \u092c\u0932 \u00d7 \u092c\u0932 \u0915\u0940 \u0926\u093f\u0936\u093e \u092e\u0947\u0902 \u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928<br><br>\n\n<div style=\"background:#e3f2fd;border-left:4px solid #1565c0;padding:8px 10px;font-weight:bold;\">\u092a\u0947\u091c 117-118 Eq 7.2 Fig 7.3:<\/div>\n<b>W = F \u00d7 s (7.2)<\/b><br>\nFig 7.2 (a)(b)(c)(d) - 5 kg \u0917\u0947\u0939\u0942\u0902 \u0915\u0940 \u092c\u094b\u0930\u0940 1 m \u0909\u0920\u093e\u0928\u093e, 3 \u092c\u094b\u0930\u0940 \u090f\u0915-\u090f\u0915 \u0915\u0930\u0915\u0947 3W, 3 \u092c\u094b\u0930\u0940 \u090f\u0915 \u0938\u093e\u0925 3F \u092c\u0932 same 3W, \u090f\u0915 \u092c\u094b\u0930\u0940 3 m \u0909\u0920\u093e\u0928\u093e 3W - \u092c\u0921\u093c\u093e \u092c\u0932 same \u0926\u0942\u0930\u0940 \u092f\u093e same \u092c\u0932 \u092c\u0921\u093c\u0940 \u0926\u0942\u0930\u0940 - \u0926\u094b\u0928\u094b\u0902 \u0938\u0947 \u091c\u094d\u092f\u093e\u0926\u093e \u0915\u093e\u0930\u094d\u092f\u0964<br><br>\n\n<div style=\"background:#fff9c4;border-left:4px solid #fbc02d;padding:8px 10px;font-weight:bold;\">\u092a\u0947\u091c 118 - 1 \u091c\u0942\u0932 \u0915\u0940 \u092a\u0930\u093f\u092d\u093e\u0937\u093e - PDF \u0932\u093e\u0907\u0928:<\/div>\n\"The SI unit of work done is joule which is represented by J.\"<br>\n\"1 J = 1 N \u00d7 1 m\" - 1 \u0928\u094d\u092f\u0942\u091f\u0928 \u0915\u093e \u0928\u093f\u092f\u0924 \u092c\u0932 \u0932\u0917\u093e\u0915\u0930 \u0935\u0938\u094d\u0924\u0941 \u0915\u094b \u092c\u0932 \u0915\u0940 \u0926\u093f\u0936\u093e \u092e\u0947\u0902 1 \u092e\u0940\u091f\u0930 \u0939\u091f\u093e\u0928\u0947 \u092a\u0930 1 \u091c\u0942\u0932 \u0915\u093e\u0930\u094d\u092f\u0964<br>\n\"Since 1 N = 1 kg m s\u207b\u00b2, note that 1 J = 1 kg m\u00b2 s\u207b\u00b2\"<br>\nFig 7.4 Force-displacement graph - \u0915\u093e\u0930\u094d\u092f = \u091b\u093e\u092f\u093e\u0902\u0915\u093f\u0924 \u0906\u092f\u0924 \u0915\u093e \u0915\u094d\u0937\u0947\u0924\u094d\u0930\u092b\u0932 = 10 N \u00d7 1 m = 10 J - \u092c\u0932 \u0928\u093f\u092f\u0924 \u0928 \u0939\u094b \u0924\u094b \u0917\u094d\u0930\u093e\u092b \u0915\u0947 \u0928\u0940\u091a\u0947 \u0915\u094d\u0937\u0947\u0924\u094d\u0930\u092b\u0932 \u092a\u094d\u0930\u093e\u0930\u0902\u092d\u093f\u0915 \u0905\u0902\u0924\u093f\u092e \u0938\u094d\u0925\u093f\u0924\u093f \u0915\u0947 \u092c\u0940\u091a\u0964<br><br>\n\n<div style=\"background:#ffebee;border-left:4px solid #b71c1c;padding:8px 10px;font-weight:bold;\">\u092a\u0947\u091c 118-119 - 7.1.1 \u0915\u093e\u0930\u094d\u092f \u0936\u0942\u0928\u094d\u092f \u0915\u092c? - PDF \u0932\u093e\u0907\u0928:<\/div>\n\"If the force acting on an object is zero, i.e., F=0, then no work is done\" - F=0 \u0924\u094b W=0<br>\n\"If there is no displacement s=0, regardless of force\" - s=0 \u0924\u094b W=0<br>\nFig 7.5 \u0926\u0940\u0935\u093e\u0930 \u0927\u0915\u0947\u0932\u0928\u093e \u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928 \u0928\u0939\u0940\u0902 \u0915\u093e\u0930\u094d\u092f \u0928\u0939\u0940\u0902 - \u092e\u093e\u0902\u0938\u092a\u0947\u0936\u093f\u092f\u093e\u0902 \u092b\u0948\u0932\u0924\u0940 \u0938\u093f\u0915\u0941\u0921\u093c\u0924\u0940 \u0905\u0902\u0926\u0930\u0942\u0928\u0940 \u090a\u0930\u094d\u091c\u093e \u0916\u0930\u094d\u091a \u0925\u0915\u093e\u0928 \u0932\u0917\u0924\u0940 \u0935\u0948\u091c\u094d\u091e\u093e\u0928\u093f\u0915 \u0905\u0930\u094d\u0925 \u092e\u0947\u0902 \u0915\u093e\u0930\u094d\u092f \u0928\u0939\u0940\u0902\u0964<br>\n\"If a force acts in a direction perpendicular to the displacement, work done is zero (Fig 7.6)\" - \u0932\u0921\u093c\u0915\u0940 \u092c\u0915\u094d\u0938\u093e \u0932\u0947\u0915\u0930 \u091a\u0932\u0924\u0940 \u090a\u092a\u0930 \u092c\u0932 \u0935\u091c\u0928 \u0938\u0902\u0924\u0941\u0932\u0928 \u0915\u094d\u0937\u0948\u0924\u093f\u091c \u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928 \u0932\u0902\u092c\u0935\u0924 \u0907\u0938\u0932\u093f\u090f \u0915\u093e\u0930\u094d\u092f \u0936\u0942\u0928\u094d\u092f\u0964<br><br>\n\n<div style=\"background:#e8f5e9;border-left:4px solid #2e7d32;padding:8px 10px;font-weight:bold;\">\u092a\u0947\u091c 119 - 7.1.2 \u0927\u0928\u093e\u0924\u094d\u092e\u0915 \u090b\u0923\u093e\u0924\u094d\u092e\u0915 \u0915\u093e\u0930\u094d\u092f - PDF \u0932\u093e\u0907\u0928:<\/div>\n\"When displacement is in same direction as applied force, work done is said to be positive.\" Fig 7.7a wheelchair same direction positive work boy on wheelchair\u0964<br>\n\"When displacement is opposite to force, work done is negative.\" Fig 7.7b goalkeeper force opposite motion negative work goalkeeper on ball\u0964<br>\n<b>Example 7.1 \u092a\u0947\u091c 119:<\/b> \u0932\u0921\u093c\u0915\u0940 \u0921\u0902\u092c\u0932 \u0909\u0920\u093e\u0924\u0940 \u090a\u092a\u0930 - \u092c\u0932 \u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928 same positive work, \u0928\u0940\u091a\u0947 \u0932\u093e\u0924\u0947 \u092a\u0915\u0921\u093c\u0928\u0947 \u092c\u0932 \u0935\u093f\u092a\u0930\u0940\u0924 negative work\u0964<br>\n<b>Example 7.2 \u092a\u0947\u091c 119:<\/b> \"Work done by goalkeeper = force \u00d7 displacement = 200 N \u00d7 (-0.15 m) = -30 J\" - \u0939\u093e\u0925 15 cm \u092a\u0940\u091b\u0947 -0.15 m \u090b\u0923\u093e\u0924\u094d\u092e\u0915 \u0915\u094d\u092f\u094b\u0902\u0915\u093f \u0917\u0947\u0902\u0926 \u0917\u0924\u093f \u0926\u093f\u0936\u093e \u092c\u0932 \u0915\u0947 \u0935\u093f\u092a\u0930\u0940\u0924\u0964<br>\n\n<\/div><\/div>\n\n<div id=\"d7h-2\" style=\"display:none;\"><div style=\"background:#1565c0;color:#fff;padding:6px 14px;border-radius:20px;font-size:13px;font-weight:bold;display:inline-block;margin-bottom:8px;\">\ud83d\udd35 \u092d\u093e\u0917 2\/5 - \u0915\u093e\u0930\u094d\u092f-\u090a\u0930\u094d\u091c\u093e \u092a\u094d\u0930\u092e\u0947\u092f \u0914\u0930 \u090a\u0930\u094d\u091c\u093e \u0930\u0942\u092a - \u092a\u0947\u091c 120-121<\/div><div style=\"background:#fff;border:1.5px solid #bf360c;border-radius:10px;padding:12px;font-size:14px;line-height:1.9;height:580px;overflow-y:auto;\">\n\n<div style=\"background:#ffebee;border-left:4px solid #b71c1c;padding:8px 10px;font-weight:bold;\">\u092a\u0947\u091c 120 Eq 7.3 - PDF \u0932\u093e\u0907\u0928:<\/div>\n<b>\"An object having the capacity to do work is said to possess energy.\"<\/b><br>\nFig 7.8a \u092b\u0940\u0932\u094d\u0921\u0930 \u0917\u0947\u0902\u0926 \u0935\u093f\u0915\u0947\u091f \u0915\u0940 \u0913\u0930, Fig 7.8b \u091a\u0932\u0924\u0940 \u0917\u0947\u0902\u0926 \u0935\u093f\u0915\u0947\u091f \u0917\u093f\u0930\u093e\u0924\u0940, Fig 7.8c \u0917\u092e\u0932\u093e \u090a\u0901\u091a\u093e\u0908 \u0938\u0947 \u0917\u093f\u0930 \u0935\u0938\u094d\u0924\u0941 damage - \u0917\u0947\u0902\u0926 \u092f\u093e \u0917\u092e\u0932\u0947 \u0928\u0947 \u0915\u093e\u0930\u094d\u092f \u0915\u0930\u0928\u0947 \u0915\u0940 \u0915\u094d\u0937\u092e\u0924\u093e \u092a\u093e\u0908\u0964<br>\n\"When positive work is done on an object, it gains energy.\"<br>\n<b>\u092a\u094d\u0930\u092e\u0947\u092f: \"work done on an object = change in its energy (7.3)\" - \u0915\u093e\u0930\u094d\u092f-\u090a\u0930\u094d\u091c\u093e \u092a\u094d\u0930\u092e\u0947\u092f<\/b><br>\n\"The theorem also holds for a system of objects or even when forces are not constant.\"<br>\n\"SI unit of energy is same as work, joule (J).\"<br>\n\u090a\u0930\u094d\u091c\u093e \u0938\u094d\u0925\u093e\u0928\u093e\u0902\u0924\u0930\u0923 \u0924\u0930\u0940\u0915\u0947 - Mechanical work \u0915\u0947 \u0905\u0932\u093e\u0935\u093e Heat - \u0926\u094b \u0935\u0938\u094d\u0924\u0941 \u0905\u0932\u0917 \u0924\u093e\u092a\u092e\u093e\u0928 \u0938\u0902\u092a\u0930\u094d\u0915 \u0917\u0930\u092e \u0938\u0947 \u0920\u0902\u0921\u0940 \u090a\u0930\u094d\u091c\u093e \u092c\u0939\u093e\u0935, Radiation \u092c\u093f\u0928\u093e \u0938\u0902\u092a\u0930\u094d\u0915 Sun energy Earth, Electric circuits, Sound waves, Nuclear reactions Sun power\u0964<br><br>\n\n<div style=\"background:#e3f2fd;border-left:4px solid #1565c0;padding:8px 10px;font-weight:bold;\">\u092a\u0947\u091c 120 Example 7.3 Carrom Fig 7.9:<\/div>\nMoving striker white coin \u0938\u0947 \u091f\u0915\u0930\u093e\u0924\u093e white black \u0938\u0947 - Striker white \u092a\u0930 positive work energy increase, white striker \u092a\u0930 opposite force negative work energy decrease, similarly white black \u092a\u0930 positive white energy increase black white \u092a\u0930 negative decrease\u0964<br><br>\n\n<div style=\"background:#fff9c4;border-left:4px solid #fbc02d;padding:8px 10px;font-weight:bold;\">\u092a\u0947\u091c 121 - 7.3 Forms of Energy Fig 7.10 - PDF \u0932\u093e\u0907\u0928:<\/div>\n\"energy is the capacity to do work\" - \u0905\u092d\u0940 \u0924\u0915 mechanical energy\u0964<br>\nFig 7.10 Different forms - PDF \u0936\u092c\u094d\u0926:<br>\n- Mechanical energy - Energy due to motion or position of objects<br>\n- Thermal energy - Energy that makes things warm or hot<br>\n- Light energy - Energy that allows us to see<br>\n- Sound energy - Energy of vibrations of air or other molecules<br>\n- Electrical energy - Energy related to position or motion of charges<br>\n- Nuclear energy - Energy stored in the nuclei of atoms<br>\n- Chemical energy - Energy stored in fuels and food in the form of chemical bonds between atoms<br>\n\"It is possible to change energy from one form to another.\"<br>\n\"electrical energy is converted into light energy in a bulb, and into thermal energy of water in an electric water heater.\"<br>\n\"chemical energy in the food we eat powers our muscles and gets converted into mechanical energy.\"<br>\n\"a ringing bell converts mechanical energy into sound energy.\"<br>\n\n<\/div><\/div>\n\n<div id=\"d7h-3\" style=\"display:none;\"><div style=\"background:#2e7d32;color:#fff;padding:6px 14px;border-radius:20px;font-size:13px;font-weight:bold;display:inline-block;margin-bottom:8px;\">\ud83d\udfe2 \u092d\u093e\u0917 3\/5 - \u0917\u0924\u093f\u091c \u0914\u0930 \u0938\u094d\u0925\u093f\u0924\u093f\u091c \u090a\u0930\u094d\u091c\u093e - \u092a\u0947\u091c 121-125<\/div><div style=\"background:#fff;border:1.5px solid #bf360c;border-radius:10px;padding:12px;font-size:14px;line-height:1.9;height:580px;overflow-y:auto;\">\n\n<div style=\"background:#e3f2fd;border-left:4px solid #1565c0;padding:8px 10px;font-weight:bold;\">\u092a\u0947\u091c 121-122 - 7.4 Mechanical Energy - 7.4.1 Kinetic Energy - PDF \u0932\u093e\u0907\u0928:<\/div>\n\"Mechanical energy is the energy that an object possesses due to its motion or position.\"<br>\n\"The energy possessed by an object due to its motion is called kinetic energy.\"<br>\nFig 7.11 - Initial velocity 0 Initial Kinetic 0, Final velocity v Final Kinetic K, Work done W=F\u00d7s, Displacement along force s<br><br>\n\n<b>\u0938\u0942\u0924\u094d\u0930 \u0928\u093f\u0915\u093e\u0932\u0928\u093e \u092a\u0947\u091c 122 Eq 7.4 Eq 7.5 Eq 7.6 - PDF \u0932\u093e\u0907\u0928:<\/b><br>\n\"v\u00b2 = u\u00b2 + 2as\" - kinematic<br>\n\"s = (v\u00b2 - u\u00b2)\/(2a) (7.4)\"<br>\n\"W = F \u00d7 s, Using Newton's second law, F=ma, we get W=ma\u00d7s\"<br>\n\"W = ma \u00d7 (v\u00b2-u\u00b2)\/(2a) = 1\/2 m(v\u00b2-u\u00b2) (7.5)\"<br>\n\"From work-energy theorem (Eq 7.3), Eq (7.5) represents change in energy of object.\"<br>\n\"If initial velocity u=0, change equal to final kinetic energy. Thus kinetic energy of mass m velocity v is\"<br>\n<b>\"K = 1\/2 mv\u00b2 (7.6)\" - \u0917\u0924\u093f\u091c \u090a\u0930\u094d\u091c\u093e<\/b><br>\n\"The SI unit of kinetic energy is joule (J). Kinetic energy has no direction.\"<br>\n\"When positive work velocity increases kinetic also increases. If negative work velocity decreases kinetic will also decrease. If no work W=0 velocity does not change kinetic remains constant.\"<br><br>\n\n<div style=\"background:#fff9c4;border-left:4px solid #fbc02d;padding:8px 10px;font-weight:bold;\">\u092a\u0947\u091c 122 Example 7.4 \u0914\u0930 7.5 - PDF \u0932\u093e\u0907\u0928:<\/div>\n<b>Example 7.4:<\/b> \"If velocity of vehicle doubles, what will its kinetic energy be?\" Answer: initial 1\/2 mv\u00b2, 2v \u21921\/2 m(2v)\u00b2=4\u00d71\/2 mv\u00b2 \u21924 times\u0964<br>\n<b>Example 7.5:<\/b> Mass 0.2 kg velocity 154.8 km\/h = 43 m s\u207b\u00b9 \"K=1\/2 mv\u00b2=1\/2\u00d70.2\u00d7(43)\u00b2=184.9 J\"<br><br>\n\n<div style=\"background:#ffebee;border-left:4px solid #b71c1c;padding:8px 10px;font-weight:bold;\">\u092a\u0947\u091c 123 Example 7.6 Jet aircraft Fig 7.12 - PDF \u0932\u093e\u0907\u0928:<\/div>\nMass 15000 kg wire backward force 367500 N stops within 100 m \"Work done by wire = F\u00d7s = 367500 N \u00d7 (-100 m)\" negative displacement opposite force<br>\n\"Change in kinetic energy = work done by wire\" \u2192 -1\/2\u00d715000\u00d7v\u00b2 = -367500\u00d7100 \u2192 v=70 m s\u207b\u00b9 =252 km h\u207b\u00b9<br><br>\n\n<div style=\"background:#e8f5e9;border-left:4px solid #2e7d32;padding:8px 10px;font-weight:bold;\">\u092a\u0947\u091c 124-125 - 7.4.2 Potential Energy - PDF \u0932\u093e\u0907\u0928:<\/div>\nFig 7.13a slingshot gulel stretched elastic band shoots forward, Fig 7.13b archery bow string bend release arrow flies\u0964<br>\nFig 7.14 spring stretch compress work deform Fig 7.14b energy stored configuration shape, release Fig 7.14c back original shape transfer stored energy to kinetic\u0964<br>\nFig 7.15a magnets unlike poles separate release move towards kinetic pea crush, Fig 7.15b electric charges separated stored energy\u0964<br>\nFig 7.16 Earth-ball system - ball and Earth attract force work against gravitational lift height, lifted force removed ball Earth towards kinetic gain - system store energy relative positions\u0964<br>\n<b>\"More generally, whenever a system of objects interacts through forces, such as gravitational, electric or magnetic forces, the system can store energy due to relative positions.\"<\/b><br>\n<b>\"The energy stored by an object as a result of its deformation or in a system of objects due to their relative positions is called potential energy.\"<\/b><br><br>\n\n<div style=\"background:#fff9c4;border-left:4px solid #fbc02d;padding:8px 10px;font-weight:bold;\">\u092a\u0947\u091c 125 Eq 7.7 Eq 7.8 - Gravitational Potential Energy - PDF \u0932\u093e\u0907\u0928:<\/div>\nActivity 7.1 sand depression - height 1 m 2 m greatest height deepest depression greater height greater potential\u0964<br>\n\"Consider object mass m lying on ground (Fig 7.18). We can define potential energy to be zero in this configuration. To raise object gradually height h, need apply force equal to mg\"<br>\n\"W = force \u00d7 displacement, W = mg \u00d7 h = mgh (7.7)\"<br>\n\"According to work-energy theorem (Eq 7.3), work done appears as change in potential energy. Thus potential energy U at height h is given by\"<br>\n<b>\"U = mgh (7.8)\"<\/b><br>\n\"The unit of potential energy is joule (J), same as work or kinetic.\"<br>\nFig 7.17 depression sand Fig 7.18 raising object h F=mg Ground<br>\n<b>Example 7.7 \u092a\u0947\u091c 126:<\/b> mass 200 g high 10 m \"potential energy = mgh =0.2\u00d710\u00d710=20 J\"<br>\n\n<\/div><\/div>\n\n<div id=\"d7h-4\" style=\"display:none;\"><div style=\"background:#ef6c00;color:#fff;padding:6px 14px;border-radius:20px;font-size:13px;font-weight:bold;display:inline-block;margin-bottom:8px;\">\ud83d\udfe0 \u092d\u093e\u0917 4\/5 - \u0938\u0902\u0930\u0915\u094d\u0937\u0923 \u0914\u0930 \u0936\u0915\u094d\u0924\u093f - \u092a\u0947\u091c 126-130<\/div><div style=\"background:#fff;border:1.5px solid #bf360c;border-radius:10px;padding:12px;font-size:14px;line-height:1.9;height:580px;overflow-y:auto;\">\n\n<div style=\"background:#e3f2fd;border-left:4px solid #1565c0;padding:8px 10px;font-weight:bold;\">\u092a\u0947\u091c 126-127 Conservation of Mechanical Energy Eq 7.9 Eq 7.10 - PDF \u0932\u093e\u0907\u0928:<\/div>\n\"The sum of kinetic and potential energy is called mechanical energy.\"<br>\nPoint A height h u=0: potential=mgh (7.9a) kinetic=0 (7.9b) mechanical=0+mgh=mgh (7.9c)<br>\nFall time t point B velocity v=gt height h' = h-1\/2 gt\u00b2<br>\nAt point B: potential=mgh' = mgh -1\/2 mg\u00b2t\u00b2? Actually mg(h-1\/2 gt\u00b2) (7.10a), kinetic=1\/2 mv\u00b2=1\/2 m(gt)\u00b2 (7.10b), mechanical=mgh-1\/2... +1\/2... =mgh (7.10c) - mechanical constant\u0964<br>\n\"lost potential energy converted into kinetic energy during motion, while mechanical energy remains constant and equal to mgh.\"<br>\n\"As object moves due to gravitational force, mechanical energy remains same, i.e., mechanical energy is conserved if no other external forces act. This is called conservation of mechanical energy.\"<br>\nActivity 7.2 pendulum Fig 7.20 paper wall horizontal line above bob - P potential mgh height bottom, Q potential zero kinetic, R kinetic zero potential same height - mechanical constant real life friction support air resistance loss slow stop\u0964<br><br>\n\n<div style=\"background:#fff9c4;border-left:4px solid #fbc02d;padding:8px 10px;font-weight:bold;\">\u092a\u0947\u091c 128 Example 7.8 \u0914\u0930 7.9 - PDF \u0932\u093e\u0907\u0928:<\/div>\n<b>Example 7.8:<\/b> child slide height h velocity bottom? \"Potential top = mgh, Kinetic bottom =1\/2 mv\u00b2, Potential converted entirely kinetic neglecting friction Equating 1\/2 mv\u00b2=mgh \u2192 v=\u221a(2gh)\" - depends only height h shape mass not matter\u0964<br>\n<b>Example 7.9 Escape ramp Fig 7.21:<\/b> Truck 10000 kg 72 km\/h =20 m\/s brakes fail 30\u00b0 sand force 50000 N opposite minimum length? Initial kinetic=1\/2\u00d710000\u00d720\u00b2=2000000 J Initial potential0 Total2000000 J, Height gained=d\/2 (hint 30\u00b0 rise 1 vertical every 2 along), Final kinetic0 Final potential=mg\u00d7d\/2=10000\u00d710\u00d7d\/2=50000\u00d7d Total final=50000d Change=50000d-2000000 Work sand=-50000\u00d7d Work-energy Work=Change \u2192-50000d=50000d-2000000 \u2192100000d=2000000 \u2192d=20 m minimum\u0964<br>\n\u092a\u0947\u091c 129 calculation: \"2000000 J = (50000+50000) N \u00d7 d, d=2000000\/100000=20 m Thus minimum length of ramp to be able to stop such truck is 20 m.\"<br><br>\n\n<div style=\"background:#ffebee;border-left:4px solid #b71c1c;padding:8px 10px;font-weight:bold;\">\u092a\u0947\u091c 129 - 7.5 Power Eq 7.11 - PDF \u0932\u093e\u0907\u0928:<\/div>\n\"Power is defined as the rate at which work is done. Mathematically, average power P is work done W, divided by time taken t, i.e., P=W\/t (7.11)\"<br>\n\"To do more work same time interval requires more power. To do same amount work shorter time also requires more power. SI unit of power is watt (W), where 1 watt =1 joule work done per second, i.e., 1 W=1 J s\u207b\u00b9\"<br>\n<b>Example 7.10 \u092a\u0947\u091c 129:<\/b> weightlifter lifts 75 kg by 2 m in 5 s \"Work done = mgh =75\u00d710\u00d72=1500 J Thus power =1500 J\/5 s=300 W\"<br>\n<b>Example 7.11 \u092a\u0947\u091c 129-130:<\/b> car 1000 kg rest 72 km\/h =20 m\/s in 10 s \"Work done by engine in 10 s = final kinetic - initial kinetic =1\/2 mv\u00b2-1\/2 mu\u00b2=1\/2\u00d71000\u00d720\u00b2-0=200000 J Power=work\/time=200000 J\/10 s=20000 W\"<br>\nThreads of Curiosity: \"You may have heard about another unit called horsepower (hp) used to measure power, especially for car engines, or pumps used to lift water. One horsepower is equal to 746 W.\"<br>\nMeet a Scientist: \"The unit of power, watt is named in honour of James Watt. He invented an efficient steam engine that could generate rotational motion and move wheels.\" \u092a\u0947\u091c 130<br>\n\n<\/div><\/div>\n\n<div id=\"d7h-5\" style=\"display:none;\"><div style=\"background:#004d40;color:#fff;padding:6px 14px;border-radius:20px;font-size:13px;font-weight:bold;display:inline-block;margin-bottom:8px;\">\u2705 \u092d\u093e\u0917 5\/5 - \u0938\u0930\u0932 \u092e\u0936\u0940\u0928\u0947\u0902 - \u092a\u0947\u091c 130-135<\/div><div style=\"background:#fff;border:1.5px solid #bf360c;border-radius:10px;padding:12px;font-size:14px;line-height:1.9;height:580px;overflow-y:auto;\">\n\n<div style=\"background:#e3f2fd;border-left:4px solid #1565c0;padding:8px 10px;font-weight:bold;\">\u092a\u0947\u091c 130 - 7.6 Simple Machines Eq 7.12 - PDF \u0932\u093e\u0907\u0928:<\/div>\n\"In everyday life, we often need to do work against gravity or other forces, such as lifting or moving heavy objects. Although total work required for a task cannot be reduced, it can be made easier by changing magnitude or direction of force that needs to be applied. Devices that help us do this are called simple machines.\"<br>\n\"We will study three simple machines - a pulley, an inclined plane and a lever - to understand how these make task feel easier. Force we apply to machine is called effort, and force that needs to be overcome is called load.\"<br>\n<b>\"To describe how machine changes magnitude of applied force, we define mechanical advantage as ratio of load to effort. It can be written as mechanical advantage = load\/effort (7.12)\"<\/b><br><br>\n\n<div style=\"background:#fff9c4;border-left:4px solid #fbc02d;padding:8px 10px;font-weight:bold;\">\u092a\u0947\u091c 130 - 7.6.1 Pulley Fig 7.23 Fig 7.24 Fig 7.25 - PDF \u0932\u093e\u0907\u0928:<\/div>\n\"A pulley is a wheel with a groove that guides a rope (Fig 7.23). A fixed pulley does not reduce magnitude of force required, it only changes its direction. It is easier for us to pull downward than to lift a load by applying upward force directly (Figs 7.24a and 7.24b). Thus pulley provides convenience by changing direction of effort. Since effort and load are equal in magnitude, mechanical advantage of fixed pulley is 1 (Eq 7.12).\"<br>\nReady to Go Beyond: \"Movable pulleys or a system of pulleys (Fig 7.25) can have a mechanical advantage greater than 1 and can lift much heavier objects with much smaller effort. In a movable pulley system, load is attached to movable pulley. One end rope is fixed to a point, while other end is free to apply effort. Pulleys are widely used in real life, such as in elevators and cranes\"<br><br>\n\n<div style=\"background:#ffebee;border-left:4px solid #b71c1c;padding:8px 10px;font-weight:bold;\">\u092a\u0947\u091c 132 - 7.6.2 Inclined plane Eq 7.13 - PDF \u0932\u093e\u0907\u0928:<\/div>\nFig 7.28a vertical height h force F' effort small distance large force, Fig 7.28b inclined length L large distance small force, Fig 7.28c larger length shallower angle smaller effort\u0964<br>\n\"Let mass be m. Then load is weight mg. Let F' be force required to raise object to height h (Fig 7.28a). Then F' is effort. Let length of inclined plane be L (Fig 7.28b).\"<br>\n\"If you move object at constant speed up inclined plane, then using Eq (7.2), total work done by you = F' \u00d7 L And using Eq (7.8), potential energy gained = mgh Thus from work-energy theorem (Eq 7.3), we obtain (ignoring friction) F'\u00d7L=mgh Or, mg\/F' = L\/h\"<br>\n<b>\"Now, mg is load and F' is effort, so using Eq (7.12), we obtain load mechanical advantage = load\/effort = mg\/F' = L\/h (7.13)\"<\/b><br>\n\"Since L is larger than h, force F' is less than mg and mechanical advantage of inclined plane is greater than 1. By further increasing L, for example, by making inclined plane longer with shallower angle (Fig 7.28c), we can further reduce effort F' required\"<br>\n<b>Example 7.12 \u092a\u0947\u091c 132:<\/b> ramp step 30 cm high width 40 cm length AC 50 cm right-angled triangle property \"Using Eq (7.13), mechanical advantage = L\/h = 50 cm\/30 cm =1.67\"<br>\nNote: \"The work done, that is product of force and displacement, is same in all cases. If force decreases, displacement increases, thereby work done remains constant.\" \u092a\u0947\u091c 132<br><br>\n\n<div style=\"background:#e8f5e9;border-left:4px solid #2e7d32;padding:8px 10px;font-weight:bold;\">\u092a\u0947\u091c 133-134 - 7.6.3 Lever Eq 7.14 Eq 7.15 Eq 7.16 Table 7.2 - PDF \u0932\u093e\u0907\u0928:<\/div>\nActivity 7.4 scale pencil erasers stapler - scale over pencil closer one end stapler other end eraser heavier stapler lifted lighter eraser - scale simple machine lever rigid bar rotate fixed point contact scale pencil\u0964<br>\n\"A lever has three main parts (Fig 7.32): (i) Fulcrum: fixed point about which lever rotates, (ii) Load: force to be overcome, and (iii) Effort: force applied. Distance of load from fulcrum is called load arm, and distance of effort from fulcrum is called effort arm.\"<br>\n\"By applying small force at one end lever, larger force can be applied on object on other end. End of lever on which smaller force F1 is applied, moves larger distance d1, while other end which applies larger force F2 to lift heavier object, moves smaller distance d2. Work done on one end transferred to other. Thus using Eq (7.1) F1\u00d7d1=F2\u00d7d2 (7.14)\"<br>\n\"Thus by increasing effort arm, lever applies larger force F2 to load compared to applied effort F1.\"<br>\nNote: \"A lever reduces force required to perform a task but not total work done.\" \u092a\u0947\u091c 133<br>\nActivity 7.5 beam balance scale string paper cups coins - beam balance lever\u0964<br>\nTable 7.1 analysis: \"beam balances when n1\u00d7L1=n2\u00d7L2 Or, effort\u00d7effort arm = load\u00d7load arm (7.15)\" \u092a\u0947\u091c 134<br>\n\"load effort arm mechanical advantage = load\/effort = effort arm\/load arm (7.16)\"<br>\n\"Hence, by increasing effort arm, lever applies larger force F2 to load than effort F1. Lever thus allows us to gain mechanical advantage equal to ratio of distances, i.e., L1\/L2.\"<br>\n\"With use of lever, effort required is generally smaller but it has to move by larger distance such that total work done by agency applying effort remains same.\"<br>\n<b>Example 7.13 \u092a\u0947\u091c 134:<\/b> seesaw four seats A,B,D,E fulcrum C AC=EC=2 m BC=DC=1 m children masses 15 kg and 30 kg sit to balanced? \"15 kg\u00d72 m=30 kg\u00d7L L=1 m Thus other child should sit at seat D.\"<br>\nTable 7.2 Classes of Levers \u092a\u0947\u091c 135: Class I Fulcrum in between Load Effort - Tongs, scissors, crowbar, pliers, balance scale, seesaw, Class II Load in between Fulcrum Effort - Lemon squeezer, wheel barrow, bottle opener, Class III Effort in between Fulcrum Load - Tongs, tweezers, broom, hammer, oar<br>\n\"In all cases, conservation of mechanical energy holds. Work we put in is equal to useful work done on load, ignoring friction. Machines do not create energy, they only help us use it more effectively.\" \u092a\u0947\u091c 135<br><br>\n\n<div style=\"background:#fff9c4;border:3px solid #fbc02d;padding:10px;border-radius:10px;text-align:center;font-weight:bold;\">\n\u2705 Chapter 7 \u092d\u093e\u0917 2 \u092a\u0930\u093f\u092d\u093e\u0937\u093e \u0938\u093f\u0926\u094d\u0927\u093e\u0902\u0924 \u0938\u0942\u0924\u094d\u0930 \u092a\u0947\u091c \u0928\u0902\u092c\u0930 \u0938\u0939\u093f\u0924 \u0936\u0941\u0926\u094d\u0927 \u0916\u0924\u094d\u092e - PDF \u0932\u093e\u0907\u0928 \u0938\u0947 \u2705<br>\n\u092a\u0947\u091c 117 Eq7.1 work=force\u00d7displacement direction, \u092a\u0947\u091c 118 Eq7.2 W=F\u00d7s 1J=1N\u00d71m=1kg m\u00b2 s\u207b\u00b2 Fig7.4 area 10J, \u0936\u0942\u0928\u094d\u092f F=0 s=0 perpendicular Fig7.5 Fig7.6, \u0927\u0928\u093e\u0924\u094d\u092e\u0915 same wheelchair \u090b\u0923\u093e\u0924\u094d\u092e\u0915 opposite goalkeeper -30J Example7.1 7.2<br>\n\u092a\u0947\u091c 120 Eq7.3 work=change energy capacity to do work, Fig7.8 Fig7.9 carrom, transfer heat radiation electric sound nuclear<br>\n\u092a\u0947\u091c 121 Fig7.10 Mechanical motion position, Thermal warm hot, Light see, Sound vibrations air, Electrical charges, Nuclear nuclei, Chemical fuels food chemical bonds - change one form another electrical\u2192light thermal, chemical food\u2192mechanical, mechanical\u2192sound bell<br>\n\u092a\u0947\u091c 122 Eq7.4 s=(v\u00b2-u\u00b2)\/2a Eq7.5 W=1\/2 m(v\u00b2-u\u00b2) Eq7.6 K=1\/2 mv\u00b2 joule no direction positive work velocity increase kinetic increase negative decrease W=0 constant - Example7.4 double 4 times, Example7.5 0.2kg 43m\/s 184.9J, Example7.6 jet 15000kg 367500N 100m v70m\/s 252km\/h<br>\n\u092a\u0947\u091c 125 Eq7.7 W=mg\u00d7h=mgh Eq7.8 U=mgh joule - Fig7.17 sand depression greater height greater potential, Fig7.18 raising h F=mg Ground - Example7.7 0.2kg 10m 20J - Potential energy stored deformation relative positions gravitational electric magnetic<br>\n\u092a\u0947\u091c 126 Eq7.9a potential mgh Eq7.9b kinetic0 Eq7.9c mechanical mgh, Eq7.10a potential mgh-... Eq7.10b kinetic 1\/2 mg\u00b2t\u00b2 Eq7.10c mechanical mgh constant conserved if no external - pendulum Fig7.20 P potential mgh Q kinetic R potential same height friction loss stop - Example7.8 v=\u221a(2gh) height only mass shape not matter, Example7.9 escape ramp 20m calculation 2000000J= (50000+50000)\u00d7d d20m \u092a\u0947\u091c129<br>\n\u092a\u0947\u091c 129 Eq7.11 Power P=W\/t watt 1W=1J s\u207b\u00b9 - Example7.10 75kg 2m 5s mgh1500J power300W, Example7.11 1000kg 72km\/h20m\/s 10s work200000J power20000W - 1 hp=746 W - watt James Watt steam engine<br>\n\u092a\u0947\u091c 130 Eq7.12 MA=load\/effort - Pulley Fig7.23 wheel groove rope fixed MA1 direction change movable Fig7.25 MA>1 elevators cranes<br>\n\u092a\u0947\u091c 132 Eq7.13 MA=mg\/F'=L\/h L>h F'<mg MA>1 increasing L shallower angle reduce effort - Example7.12 30cm 40cm 50cm MA1.67 - work product same force decreases displacement increases constant<br>\n\u092a\u0947\u091c 133 Eq7.14 F1\u00d7d1=F2\u00d7d2 effort arm load arm - Eq7.15 n1\u00d7L1=n2\u00d7L2 effort\u00d7effort arm=load\u00d7load arm Eq7.16 MA=effort arm\/load arm L1\/L2 - Example7.13 seesaw 15kg 2m=30kg\u00d7L L1m seat D - Table7.2 Class I Fulcrum between scissors seesaw Class II Load between wheel barrow Class III Effort between tweezers broom - Machines do not create energy only use effectively<br>\n\u0905\u0917\u0932\u093e \u092d\u093e\u0917 \u092a\u094d\u0930\u0936\u094d\u0928\u093e\u0935\u0932\u0940 \u092c\u0928\u093e\u090a\u0901 \u0938\u0930?\n<\/div>\n\n<\/div><\/div>\n<\/div>\n\n<div style=\"background:#bf360c;padding:12px;display:flex;justify-content:space-between;align-items:center;\">\n<button type=\"button\" id=\"d7hp\" style=\"background:#ffcc00;color:#000;border:3px solid #fff;border-radius:30px;padding:10px 22px;font-weight:bold;cursor:pointer;min-width:100px;\">&larr; \u092a\u0940\u091b\u0947<\/button>\n<span id=\"d7hi\" style=\"background:#fff;color:#bf360c;padding:8px 20px;border-radius:20px;font-weight:bold;\">1 \/ 5<\/span>\n<button type=\"button\" id=\"d7hn\" style=\"background:#00e676;color:#000;border:3px solid #fff;border-radius:30px;padding:10px 22px;font-weight:bold;cursor:pointer;min-width:100px;\">\u0906\u0917\u0947 &rarr;<\/button>\n<\/div>\n<\/div>\n\n<script>\n(function(){\nvar c=1,t=5;\nfunction s(n){\nfor(var i=1;i<=t;i++){\nvar el=document.getElementById('d7h-'+i);\nif(el)el.style.display=(i===n?'block':'none');\n}\ndocument.getElementById('d7hi').textContent=n+' \/ '+t;\nc=n;\n}\ndocument.getElementById('d7hn').onclick=function(){var n=c+1;if(n>t)n=1;s(n);};\ndocument.getElementById('d7hp').onclick=function(){var n=c-1;if(n<1)n=t;s(n);};\n})();\n<\/script><\/div><\/div><\/div><\/div><div id=\"pg-838-2\"  class=\"panel-grid panel-no-style\" ><div id=\"pgc-838-2-0\"  class=\"panel-grid-cell\" ><div id=\"panel-838-2-0-0\" class=\"widget_text so-panel widget widget_custom_html panel-first-child panel-last-child\" data-index=\"2\" ><div class=\"textwidget custom-html-widget\"><div id=\"CH7-EXER-HI\" style=\"max-width:860px;margin:12px auto;border:4px solid #bf360c;border-radius:14px;background:#fbe9e7;font-family:'Noto Sans Devanagari',Arial,sans-serif;overflow:hidden;\">\n<div style=\"background:#bf360c;padding:10px;text-align:center;\"><span style=\"background:#fff;color:#bf360c;padding:7px 20px;border-radius:20px;font-weight:bold;font-size:14px;\">\u0905\u0927\u094d\u092f\u093e\u092f 7 - \u0938\u093e\u0930\u0940 \u092a\u094d\u0930\u0936\u094d\u0928\u093e\u0935\u0932\u0940 - \u0915\u094b\u0908 \u092a\u094d\u0930\u0936\u094d\u0928 \u0928\u0939\u0940\u0902 \u091b\u0942\u091f\u093e - \u092a\u0947\u091c \u0938\u0939\u093f\u0924<\/span><\/div>\n\n<div style=\"padding:10px 12px;\">\n<div id=\"ex7-1\" style=\"display:block;\"><div style=\"background:#b71c1c;color:#fff;padding:6px 14px;border-radius:20px;font-size:13px;font-weight:bold;display:inline-block;margin-bottom:8px;\">\ud83d\udd34 \u092d\u093e\u0917 1\/5 - Pause and Ponder Q1-Q6 \u092a\u0947\u091c 119-126<\/div><div style=\"background:#fff;border:1.5px solid #bf360c;border-radius:10px;padding:12px;font-size:14px;line-height:1.9;height:580px;overflow-y:auto;\">\n\n<div style=\"background:#ffebee;border-left:4px solid #b71c1c;padding:8px 10px;font-weight:bold;\">\u092a\u0947\u091c 119 Pause and Ponder:<\/div>\n<b>Q1. \u092a\u093f\u091b\u0932\u0947 \u0905\u0927\u094d\u092f\u093e\u092f \u092e\u0947\u0902 \u092d\u093e\u0930\u094b\u0924\u094d\u0924\u094b\u0932\u0915 \u092c\u093e\u0930\u092c\u0947\u0932 \u0938\u094d\u0925\u093f\u0930 \u092a\u0915\u0921\u093c\u0947 \u0939\u0948 \u091a\u093f\u0924\u094d\u0930 6.8 - \u0915\u094d\u092f\u093e \u0935\u0939 \u092c\u093e\u0930\u092c\u0947\u0932 \u092a\u0930 \u0915\u094b\u0908 \u0915\u093e\u0930\u094d\u092f \u0915\u0930 \u0930\u0939\u0940 \u0939\u0948?<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: \u0928\u0939\u0940\u0902 - s=0 \u0907\u0938\u0932\u093f\u090f W=F\u00d7s=0 - \u0935\u0948\u091c\u094d\u091e\u093e\u0928\u093f\u0915 \u0905\u0930\u094d\u0925 \u092e\u0947\u0902 \u0915\u093e\u0930\u094d\u092f \u0928\u0939\u0940\u0902 - \u092a\u0947\u091c 119 PDF \u0932\u093e\u0907\u0928 \"if there is no displacement s=0, regardless of force no work\"<\/b><br><br>\n<b>Q2. \u0916\u0941\u0930\u0926\u0930\u0940 \u0938\u0924\u0939 \u092a\u0930 \u091a\u0932\u0924\u0940 \u0938\u093f\u0915\u094d\u0915\u094b\u0902 \u0915\u0940 \u0922\u0947\u0930\u0940 \u092a\u0930 \u0918\u0930\u094d\u0937\u0923 \u0926\u094d\u0935\u093e\u0930\u093e \u0915\u093f\u092f\u093e \u0917\u092f\u093e \u0915\u093e\u0930\u094d\u092f \u091a\u093f\u0924\u094d\u0930 6.13c - \u0927\u0928\u093e\u0924\u094d\u092e\u0915 \u090b\u0923\u093e\u0924\u094d\u092e\u0915 \u092f\u093e \u0936\u0942\u0928\u094d\u092f?<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: \u090b\u0923\u093e\u0924\u094d\u092e\u0915 - \u0918\u0930\u094d\u0937\u0923 \u0917\u0924\u093f \u0915\u0947 \u0935\u093f\u092a\u0930\u0940\u0924 \u0907\u0938\u0932\u093f\u090f \u092c\u0932 \u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928 \u0935\u093f\u092a\u0930\u0940\u0924 negative work - \u092a\u0947\u091c 119<\/b><br><br>\n\n<div style=\"background:#e3f2fd;border-left:4px solid #1565c0;padding:8px 10px;font-weight:bold;\">\u092a\u0947\u091c 121 Q3:<\/div>\n<b>Q3. \u091c\u092c \u0906\u092a \u0938\u092e\u0924\u0932 \u0938\u0921\u093c\u0915 \u092a\u0930 \u0938\u093e\u0907\u0915\u093f\u0932 \u091a\u0932\u093e\u0924\u0947 \u0939\u0948\u0902 \u0924\u094b \u092e\u093e\u0902\u0938\u092a\u0947\u0936\u093f\u092f\u094b\u0902 \u0915\u0940 \u090a\u0930\u094d\u091c\u093e \u0915\u093f\u0928 \u0930\u0942\u092a\u094b\u0902 \u092e\u0947\u0902 \u0926\u093f\u0916\u0924\u0940 \u0939\u0948?<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: \u092e\u093e\u0902\u0938\u092a\u0947\u0936\u0940 \u0930\u093e\u0938\u093e\u092f\u0928\u093f\u0915 \u2192 \u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 \u0938\u093e\u0907\u0915\u093f\u0932 \u0917\u0924\u093f\u091c + \u090a\u0937\u094d\u092e\u0940\u092f \u0918\u0930\u094d\u0937\u0923 + \u0927\u094d\u0935\u0928\u093f - Fig 7.10 \u0930\u0942\u092a Mechanical Thermal Sound - \u092a\u0947\u091c 121<\/b><br><br>\n\n<div style=\"background:#fff9c4;border-left:4px solid #fbc02d;padding:8px 10px;font-weight:bold;\">\u092a\u0947\u091c 123 Q4 Q5:<\/div>\n<b>Q4. \u0926\u094b \u0935\u0938\u094d\u0924\u0941\u090f\u0901 A \u0914\u0930 B \u0926\u094d\u0930\u0935\u094d\u092f\u092e\u093e\u0928 m \u0914\u0930 4m \u0915\u0940 \u0917\u0924\u093f\u091c \u090a\u0930\u094d\u091c\u093e same \u0939\u0948 - \u0935\u0947\u0917 \u092a\u0930\u093f\u092e\u093e\u0923 \u0905\u0928\u0941\u092a\u093e\u0924 \u0915\u094d\u092f\u093e?<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: K same 1\/2 m vA\u00b2 = 1\/2 \u00d74m\u00d7vB\u00b2 \u2192 vA\u00b2=4vB\u00b2 \u2192 vA\/vB=2\/1 \u2192 2:1 - \u092a\u0947\u091c 123 Example 7.4 \u091c\u0948\u0938\u093e<\/b><br><br>\n<b>Q5. \u0928\u093f\u092f\u0924 \u0935\u0947\u0917 \u0938\u0947 \u091a\u0932\u0924\u0940 \u0935\u0938\u094d\u0924\u0941 \u0915\u0940 \u0917\u0924\u093f\u091c \u090a\u0930\u094d\u091c\u093e \u0938\u094d\u0925\u093f\u0924\u093f \u0915\u0947 \u0938\u093e\u0925 \u092c\u0926\u0932\u0924\u0940 \u0939\u0948 \u0915\u094d\u092f\u093e?<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: \u0928\u0939\u0940\u0902 - K=1\/2 mv\u00b2 \u0935\u0947\u0917 \u0928\u093f\u092f\u0924 \u0924\u094b K same \u0938\u094d\u0925\u093f\u0924\u093f \u0938\u0947 \u0938\u094d\u0935\u0924\u0902\u0924\u094d\u0930 - \u092a\u0947\u091c 123<\/b><br><br>\n\n<div style=\"background:#e8f5e9;border-left:4px solid #2e7d32;padding:8px 10px;font-weight:bold;\">\u092a\u0947\u091c 126 Q6:<\/div>\n<b>Q6. \u0915\u094d\u092f\u093e \u092a\u0943\u0925\u094d\u0935\u0940 \u0938\u0924\u0939 \u0915\u0947 \u092a\u093e\u0938 \u0935\u0938\u094d\u0924\u0941 \u0915\u0940 \u0938\u094d\u0925\u093f\u0924\u093f\u091c \u090a\u0930\u094d\u091c\u093e \u092c\u0926\u0932\u0924\u0940 \u0939\u0948 \u092f\u0926\u093f \u0935\u0939 \u0915\u094d\u0937\u0948\u0924\u093f\u091c \u0926\u093f\u0936\u093e \u092e\u0947\u0902 \u0928\u093f\u092f\u0924 \u0935\u0947\u0917 \u0938\u0947 \u091a\u0932\u0924\u0940 \u0939\u0948? \u092f\u0926\u093f \u0935\u0938\u094d\u0924\u0941 \u0927\u0940\u0930\u0947-\u0927\u0940\u0930\u0947 \u0932\u0902\u092c\u0935\u0924 \u090a\u092a\u0930 \u0909\u0920\u093e\u0908 \u091c\u093e\u090f \u0924\u094b \u0915\u094d\u092f\u093e?<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: \u0915\u094d\u0937\u0948\u0924\u093f\u091c \u0928\u093f\u092f\u0924 \u0935\u0947\u0917 - \u090a\u0901\u091a\u093e\u0908 same \u0907\u0938\u0932\u093f\u090f U=mgh same \u092a\u0930\u093f\u0935\u0930\u094d\u0924\u0928 \u0928\u0939\u0940\u0902\u0964 \u0932\u0902\u092c\u0935\u0924 \u090a\u092a\u0930 \u0909\u0920\u093e\u0928\u0947 \u092a\u0930 \u090a\u0901\u091a\u093e\u0908 \u092c\u0922\u093c\u0940 U=mgh \u092c\u0922\u093c\u0940 - \u092a\u0947\u091c 126 Example 7.7 \u091c\u0948\u0938\u093e<\/b><br><br>\n\n<div style=\"background:#ffebee;border-left:4px solid #b71c1c;padding:8px 10px;font-weight:bold;\">\u092a\u0947\u091c 129 Q7 Q8:<\/div>\n<b>Q7. \u091a\u093f\u0924\u094d\u0930 7.19 \u092e\u0947\u0902 \u0926\u0930\u094d\u0936\u093e\u0908 \u0938\u094d\u0925\u093f\u0924\u093f \u0915\u0947 \u0932\u093f\u090f \u091c\u092e\u0940\u0928 \u0938\u0947 \u091f\u0915\u0930\u093e\u0928\u0947 \u0938\u0947 \u0920\u0940\u0915 \u092a\u0939\u0932\u0947 \u0917\u0947\u0902\u0926 \u0915\u0940 \u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 \u090a\u0930\u094d\u091c\u093e \u0928\u093f\u0915\u093e\u0932\u094b \u0914\u0930 \u0926\u093f\u0916\u093e\u0913 \u0915\u093f \u0907\u0938 \u0938\u094d\u0925\u093f\u0924\u093f \u092e\u0947\u0902 \u092d\u0940 mgh \u0939\u0940 \u0939\u0948\u0964<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: Point A h \u092a\u0930 mgh 0+mgh=mgh Eq7.9c, Point B h' = h-1\/2 gt\u00b2 potential mgh' Eq7.10a kinetic 1\/2 m(gt)\u00b2 Eq7.10b mechanical mgh Eq7.10c - \u091c\u092e\u0940\u0928 \u092a\u0930 h'=0 potential0 kinetic mgh mechanical mgh \u0939\u0940 - \u0938\u0902\u0930\u0915\u094d\u0937\u0923 - \u092a\u0947\u091c 126-129<\/b><br><br>\n<b>Q8. \u0906\u092a\u0928\u0947 \u0938\u093e\u0907\u0902\u0938 \u092a\u093e\u0930\u094d\u0915 \u092e\u0947\u0902 \u091a\u093f\u0924\u094d\u0930 7.22 \u091c\u0948\u0938\u093e \u092a\u094d\u0930\u0926\u0930\u094d\u0936\u0928 \u0926\u0947\u0916\u093e \u0939\u094b\u0917\u093e \u091c\u0939\u093e\u0901 \u0917\u0947\u0902\u0926 \u0938\u092c\u0938\u0947 \u090a\u0901\u091a\u0947 \u092c\u093f\u0902\u0926\u0941 \u0938\u0947 \u091b\u094b\u0921\u093c\u0940 \u091c\u093e\u0924\u0940 \u0939\u0948 - \u092c\u093f\u0902\u0926\u0941 A B C \u092a\u0930 \u0917\u0924\u093f\u091c \u0914\u0930 \u0938\u094d\u0925\u093f\u0924\u093f\u091c \u090a\u0930\u094d\u091c\u093e \u0915\u0948\u0938\u0947 \u092c\u0926\u0932\u0924\u0940 \u0939\u0948? \u092c\u093e\u0926 \u0915\u0947 \u092c\u093f\u0902\u0926\u0941 C D E \u0915\u0940 \u090a\u0901\u091a\u093e\u0908 \u092a\u093f\u091b\u0932\u0947 \u0938\u0947 \u0915\u092e \u0915\u094d\u092f\u094b\u0902 \u0939\u094b\u0924\u0940 \u0939\u0948? \u0915\u094d\u092f\u093e \u0907\u0938\u0915\u093e \u0918\u0930\u094d\u0937\u0923 \u0938\u0947 \u0916\u094b\u0908 \u090a\u0930\u094d\u091c\u093e \u0938\u0947 \u0938\u0902\u092c\u0902\u0927 \u0939\u0948?<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: A \u092a\u0930 \u0938\u094d\u0925\u093f\u0924\u093f\u091c \u0905\u0927\u093f\u0915\u0924\u092e mgh \u0917\u0924\u093f\u091c 0, B \u0928\u0940\u091a\u0947 \u0938\u094d\u0925\u093f\u0924\u093f\u091c \u0915\u092e \u0917\u0924\u093f\u091c \u0905\u0927\u093f\u0915, C \u090a\u092a\u0930 \u092b\u093f\u0930 \u0938\u094d\u0925\u093f\u0924\u093f\u091c \u092c\u0922\u093c\u0940 \u0917\u0924\u093f\u091c \u0918\u091f\u0940 - \u0918\u0930\u094d\u0937\u0923 \u0939\u0935\u093e \u092a\u094d\u0930\u0924\u093f\u0930\u094b\u0927 \u0938\u0947 \u090a\u0930\u094d\u091c\u093e \u0939\u093e\u0928\u093f \u090a\u0937\u094d\u092e\u093e \u0927\u094d\u0935\u0928\u093f \u092e\u0947\u0902 \u0907\u0938\u0932\u093f\u090f \u092c\u093e\u0926 \u0915\u0947 \u092c\u093f\u0902\u0926\u0941 \u090a\u0901\u091a\u093e\u0908 \u0915\u092e - Mechanical energy not conserved friction loss - \u092a\u0947\u091c 129 Fig 7.22<\/b><br>\n\n<\/div><\/div>\n\n<div id=\"ex7-2\" style=\"display:none;\"><div style=\"background:#1565c0;color:#fff;padding:6px 14px;border-radius:20px;font-size:13px;font-weight:bold;display:inline-block;margin-bottom:8px;\">\ud83d\udd35 \u092d\u093e\u0917 2\/5 - Pause Q9-Q13 \u092a\u0947\u091c 132-135 + True False<\/div><div style=\"background:#fff;border:1.5px solid #bf360c;border-radius:10px;padding:12px;font-size:14px;line-height:1.9;height:580px;overflow-y:auto;\">\n\n<div style=\"background:#fff9c4;border-left:4px solid #fbc02d;padding:8px 10px;font-weight:bold;\">\u092a\u0947\u091c 132 Q9 Q10:<\/div>\n<b>Q9. \u092a\u0939\u093e\u0921\u093c\u094b\u0902 \u092a\u0930 \u0938\u0921\u093c\u0915\u0947\u0902 \u0938\u0940\u0927\u0940 \u090a\u092a\u0930 \u091c\u093e\u0928\u0947 \u0915\u0947 \u092c\u091c\u093e\u092f \u0918\u0941\u092e\u093e\u0935\u0926\u093e\u0930 \u0939\u0932\u094d\u0915\u0940 \u0922\u093e\u0932 \u092e\u0947\u0902 \u0915\u094d\u092f\u094b\u0902 \u092c\u0928\u093e\u0908 \u091c\u093e\u0924\u0940 \u0939\u0948\u0902 \u091a\u093f\u0924\u094d\u0930 4.26?<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: \u0906\u0928\u0924 \u0924\u0932 MA=L\/h Eq7.13 - L \u092c\u0922\u093c\u093e \u0939\u0932\u094d\u0915\u0940 \u0922\u093e\u0932 \u0924\u094b \u092a\u094d\u0930\u092f\u093e\u0938 F' = mgh\/L \u0915\u092e \u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 \u0932\u093e\u092d >1 \u0907\u0938\u0932\u093f\u090f \u092d\u093e\u0930\u0940 \u0935\u093e\u0939\u0928 \u0915\u092e \u092c\u0932 \u092e\u0947\u0902 \u090a\u092a\u0930 - \u0915\u093e\u0930\u094d\u092f same \u092c\u0932 \u0918\u091f\u093e \u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928 \u092c\u0922\u093c\u093e - \u092a\u0947\u091c 132 Note same work<\/b><br><br>\n<b>Q10. \u090a\u0901\u091a\u0940 \u092e\u0902\u091c\u093f\u0932 \u0924\u0915 \u092a\u0939\u0941\u0901\u091a\u0928\u0947 \u0915\u0947 \u0932\u093f\u090f \u0906\u0928\u0924 \u0938\u0940\u0922\u093c\u0940 \u0938\u0940\u0927\u0940 \u0938\u0940\u0922\u093c\u0940 \u0915\u0940 \u0924\u0941\u0932\u0928\u093e \u092e\u0947\u0902 \u0906\u0938\u093e\u0928 \u0932\u0917\u0924\u0940 \u0939\u0948 \u091a\u093f\u0924\u094d\u0930 7.30 - \u0915\u094d\u092f\u094b\u0902?<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: Same \u0906\u0928\u0924 \u0924\u0932 - \u0906\u0928\u0924 \u0938\u0940\u0922\u093c\u0940 L \u092c\u0921\u093c\u093e h \u0938\u0947 MA=L\/h>1 \u092a\u094d\u0930\u092f\u093e\u0938 \u0915\u092e - \u0938\u0940\u0927\u0940 \u0938\u0940\u0922\u093c\u0940 L=h MA=1 \u092a\u094d\u0930\u092f\u093e\u0938=\u092d\u093e\u0930 mg \u0905\u0927\u093f\u0915 - \u092a\u0947\u091c 132-133<\/b><br><br>\n\n<div style=\"background:#e3f2fd;border-left:4px solid #1565c0;padding:8px 10px;font-weight:bold;\">\u092a\u0947\u091c 135 Q11 Q12 Q13:<\/div>\n<b>Q11. \u0921\u093f\u092c\u094d\u092c\u0947 \u0915\u093e \u0922\u0915\u094d\u0915\u0928 \u091a\u092e\u094d\u092e\u091a \u0938\u0947 \u0916\u094b\u0932\u0928\u093e \u091a\u093f\u0924\u094d\u0930 7.35 \u0938\u0947 \u0906\u0938\u093e\u0928 \u0915\u094d\u092f\u094b\u0902?<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: \u091a\u092e\u094d\u092e\u091a \u0909\u0924\u094d\u0924\u094b\u0932\u0915 Class I - \u0906\u0932\u0902\u092c \u0915\u093f\u0928\u093e\u0930\u093e - \u092a\u094d\u0930\u092f\u093e\u0938 \u092d\u0941\u091c\u093e \u092c\u0921\u093c\u0940 \u092d\u093e\u0930 \u092d\u0941\u091c\u093e \u091b\u094b\u091f\u0940 MA=effort arm\/load arm Eq7.16 >1 \u092c\u0932 \u092c\u0922\u093c\u093e - \u092a\u0947\u091c 135<\/b><br><br>\n<b>Q12. \u0915\u0920\u093f\u0928 \u0935\u0938\u094d\u0924\u0941 \u0915\u093e\u091f\u0928\u0947 \u0915\u0947 \u0932\u093f\u090f \u0915\u0948\u0902\u091a\u0940 \u092e\u0947\u0902 \u0935\u0938\u094d\u0924\u0941 \u0915\u094b \u0906\u0932\u0902\u092c \u0915\u0947 \u092a\u093e\u0938 \u0915\u094d\u092f\u094b\u0902 \u0927\u0915\u0947\u0932\u0924\u0947 \u0939\u0948\u0902?<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: \u092d\u093e\u0930 \u092d\u0941\u091c\u093e \u091b\u094b\u091f\u0940 \u0915\u0930\u0928\u0947 \u0938\u0947 MA=effort arm\/load arm \u092c\u0922\u093c\u093e \u0905\u0927\u093f\u0915 \u092c\u0932 \u092d\u093e\u0930 \u092a\u0930 - \u0915\u0948\u0902\u091a\u0940 Class I - \u092a\u0947\u091c 133 Eq7.14 F1d1=F2d2<\/b><br><br>\n<b>Q13. \u0907\u0924\u093f\u0939\u093e\u0938 \u092e\u0947\u0902 \u0938\u0924\u0924 \u0917\u0924\u093f \u092e\u0936\u0940\u0928\u0947\u0902 \u092a\u0939\u093f\u090f \u0935\u091c\u0928 \u091a\u0941\u0902\u092c\u0915 \u0938\u0947 \u092a\u094d\u0930\u0938\u094d\u0924\u093e\u0935\u093f\u0924 \u0932\u0947\u0915\u093f\u0928 \u0915\u094b\u0908 \u0915\u093e\u092e \u0928\u0939\u0940\u0902 \u0915\u0930\u0924\u0940 - \u0938\u092d\u0940 \u0905\u0938\u0932\u0940 \u092e\u0936\u0940\u0928\u0947\u0902 \u0927\u0940\u0930\u0947 \u0930\u0941\u0915 \u0915\u094d\u092f\u094b\u0902 \u091c\u093e\u0924\u0940 \u0939\u0948\u0902? \u0915\u093e\u0930\u094d\u092f \u0914\u0930 \u090a\u0930\u094d\u091c\u093e \u0915\u0947 \u092a\u0926\u094b\u0902 \u092e\u0947\u0902 \u0938\u092e\u091d\u093e\u0913\u0964<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: \u0918\u0930\u094d\u0937\u0923 \u0939\u0935\u093e \u092a\u094d\u0930\u0924\u093f\u0930\u094b\u0927 \u0938\u0947 \u090a\u0930\u094d\u091c\u093e \u0939\u093e\u0928\u093f \u090a\u0937\u094d\u092e\u093e \u0927\u094d\u0935\u0928\u093f \u092e\u0947\u0902 - Mechanical energy conserved \u0928\u0939\u0940\u0902 external forces - Machines do not create energy only use more effectively \u092a\u0947\u091c 135 - \u092c\u093f\u0928\u093e \u0908\u0902\u0927\u0928 \u092c\u093f\u091c\u0932\u0940 \u0938\u0924\u0924 \u0915\u093e\u0930\u094d\u092f \u0928\u0939\u0940\u0902 - What If perpetual motion possible once started continue useful work forever without fuel?<\/b><br><br>\n\n<div style=\"background:#ffebee;border-left:4px solid #b71c1c;padding:8px 10px;font-weight:bold;\">\u092a\u0947\u091c 136 Q1 True False - PDF \u0932\u093e\u0907\u0928:<\/div>\n<b>Q1. \u0938\u0924\u094d\u092f \u0905\u0938\u0924\u094d\u092f \u092c\u0924\u093e\u0913:<\/b><br>\n(i) \u092c\u0932 \u0932\u0917\u093e\u092f\u093e \u0935\u0938\u094d\u0924\u0941 \u0928\u0939\u0940\u0902 \u0939\u091f\u0940 \u092b\u093f\u0930 \u092d\u0940 \u0915\u093e\u0930\u094d\u092f \u0915\u0939\u093e \u091c\u093e\u0924\u093e \u0939\u0948 - \u0905\u0938\u0924\u094d\u092f False - W=F\u00d7s s=0 \u0924\u094b W=0 \u092a\u0947\u091c 118-119<br>\n(ii) \u092c\u093e\u0932\u094d\u091f\u0940 \u0932\u0902\u092c\u0935\u0924 \u090a\u092a\u0930 \u0909\u0920\u093e\u0928\u0947 \u092a\u0930 \u092c\u093e\u0932\u094d\u091f\u0940 \u092a\u0930 \u0927\u0928\u093e\u0924\u094d\u092e\u0915 \u0915\u093e\u0930\u094d\u092f - \u0938\u0924\u094d\u092f True - \u092c\u0932 \u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928 same positive \u092a\u0947\u091c 119<br>\n(iii) \u0915\u093e\u0930\u094d\u092f \u0914\u0930 \u090a\u0930\u094d\u091c\u093e \u0926\u094b\u0928\u094b\u0902 \u0915\u093e SI \u092e\u093e\u0924\u094d\u0930\u0915 \u091c\u0942\u0932 J - \u0938\u0924\u094d\u092f True - \u092a\u0947\u091c 120 Eq7.3 unit joule<br>\n(iv) \u0917\u0924\u093f\u0939\u0940\u0928 \u0916\u093f\u0902\u091a\u0940 \u0930\u092c\u0930 \u092c\u0948\u0902\u0921 \u092e\u0947\u0902 \u0917\u0924\u093f\u091c \u090a\u0930\u094d\u091c\u093e - \u0905\u0938\u0924\u094d\u092f False - \u0938\u094d\u0925\u093f\u0924\u093f\u091c \u090a\u0930\u094d\u091c\u093e \u0939\u094b\u0924\u0940 \u0939\u0948 \u0917\u0924\u093f\u091c 0 \u092a\u0947\u091c 124 potential energy stored deformation<br>\n(v) \u090a\u0930\u094d\u091c\u093e \u090f\u0915 \u0930\u0942\u092a \u0938\u0947 \u0926\u0942\u0938\u0930\u0947 \u092e\u0947\u0902 \u092c\u0926\u0932 \u0938\u0915\u0924\u0940 \u0939\u0948 - \u0938\u0924\u094d\u092f True - \u092a\u0947\u091c 121 Fig7.10 electrical\u2192light thermal chemical\u2192mechanical<br>\n<b>\u0909\u0924\u094d\u0924\u0930: (i)F (ii)T (iii)T (iv)F (v)T - At a Glance \u092a\u0947\u091c 136<\/b><br>\n\n<\/div><\/div>\n\n<div id=\"ex7-3\" style=\"display:none;\"><div style=\"background:#2e7d32;color:#fff;padding:6px 14px;border-radius:20px;font-size:13px;font-weight:bold;display:inline-block;margin-bottom:8px;\">\ud83d\udfe2 \u092d\u093e\u0917 3\/5 - Fill Blanks \u0914\u0930 Energy Transformation \u092a\u0947\u091c 137<\/div><div style=\"background:#fff;border:1.5px solid #bf360c;border-radius:10px;padding:12px;font-size:14px;line-height:1.9;height:580px;overflow-y:auto;\">\n\n<div style=\"background:#fff9c4;border-left:4px solid #fbc02d;padding:8px 10px;font-weight:bold;\">\u092a\u0947\u091c 137 Q2 Fill in blanks - PDF \u0932\u093e\u0907\u0928:<\/div>\n<b>(i) Work done = ______ \u00d7 ______ (in direction of force)<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: force \u00d7 displacement - W=F\u00d7s Eq7.2 \u092a\u0947\u091c 118<\/b><br><br>\n<b>(ii) 1 joule work done when force of ______ newton displaces object by 1 metre in direction of force<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: 1 newton - 1 J =1 N\u00d71 m \u092a\u0947\u091c 118<\/b><br><br>\n<b>(iii) Expression for kinetic energy body mass m velocity v is ______<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: 1\/2 mv\u00b2 - K=1\/2 mv\u00b2 Eq7.6 \u092a\u0947\u091c 122<\/b><br><br>\n<b>(iv) Potential energy object mass m at small height h from Earth's surface is ______<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: mgh - U=mgh Eq7.8 \u092a\u0947\u091c 125<\/b><br><br>\n<b>(v) Power defined as ______ at which work is done<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: rate - Power P=W\/t Eq7.11 \u092a\u0947\u091c 129 rate at which work is done<\/b><br><br>\n\n<div style=\"background:#e3f2fd;border-left:4px solid #1565c0;padding:8px 10px;font-weight:bold;\">\u092a\u0947\u091c 137 Q3 - Ball thrown upwards reaches highest point tick correct:<\/div>\n<b>Q3. \u0917\u0947\u0902\u0926 \u090a\u092a\u0930 \u092b\u0947\u0902\u0915\u0940 \u0909\u091a\u094d\u091a\u0924\u092e \u092c\u093f\u0902\u0926\u0941 \u092a\u0930 \u0915\u094c\u0928 \u0938\u093e \u0915\u0925\u0928 \u0938\u0939\u0940? (i) \u0917\u0947\u0902\u0926 \u092a\u0930 \u092c\u0932 \u0936\u0942\u0928\u094d\u092f (ii) \u0924\u094d\u0935\u0930\u0923 \u0936\u0942\u0928\u094d\u092f (iii) \u0917\u0924\u093f\u091c \u090a\u0930\u094d\u091c\u093e \u0936\u0942\u0928\u094d\u092f (iv) \u0938\u094d\u0925\u093f\u0924\u093f\u091c \u090a\u0930\u094d\u091c\u093e \u0905\u0927\u093f\u0915\u0924\u092e<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: (iii) \u0914\u0930 (iv) \u0938\u0939\u0940 - \u0909\u091a\u094d\u091a\u0924\u092e \u092c\u093f\u0902\u0926\u0941 v=0 \u0907\u0938\u0932\u093f\u090f K=1\/2 mv\u00b2=0, U=mgh \u0905\u0927\u093f\u0915\u0924\u092e - (i) \u0917\u0932\u0924 \u092c\u0932 mg \u0928\u0940\u091a\u0947 \u0915\u093e\u092e \u0915\u0930\u0924\u093e (ii) \u0917\u0932\u0924 \u0924\u094d\u0935\u0930\u0923 g=10 m\/s\u00b2 \u0928\u0940\u091a\u0947 - \u092a\u0947\u091c 126-127<\/b><br><br>\n\n<div style=\"background:#ffebee;border-left:4px solid #b71c1c;padding:8px 10px;font-weight:bold;\">\u092a\u0947\u091c 137 Q4 Energy Transformation - PDF \u0932\u093e\u0907\u0928:<\/div>\n<b>Q4. \u092a\u094d\u0930\u0924\u094d\u092f\u0947\u0915 \u0938\u094d\u0925\u093f\u0924\u093f \u092e\u0947\u0902 \u090a\u0930\u094d\u091c\u093e \u0930\u0942\u092a\u093e\u0902\u0924\u0930\u0923 \u092a\u0939\u091a\u093e\u0928\u094b: (i) \u091f\u094d\u0930\u0915 \u092a\u0939\u093e\u0921\u093c\u0940 \u090a\u092a\u0930 (ii) \u0918\u0921\u093c\u0940 \u0938\u094d\u092a\u094d\u0930\u093f\u0902\u0917 \u0916\u0941\u0932\u0928\u093e (iii) \u0939\u0930\u0947 \u092a\u0924\u094d\u0924\u094b\u0902 \u092e\u0947\u0902 \u092a\u094d\u0930\u0915\u093e\u0936 \u0938\u0902\u0936\u094d\u0932\u0947\u0937\u0923 (iv) \u092c\u093e\u0901\u0927 \u0938\u0947 \u092a\u093e\u0928\u0940 \u092c\u0939\u0928\u093e (v) \u092e\u093e\u091a\u093f\u0938 \u091c\u0932\u0928\u093e (vi) \u092a\u091f\u093e\u0916\u093e \u092b\u091f\u0928\u093e (vii) \u092e\u093e\u0907\u0915\u094d\u0930\u094b\u092b\u094b\u0928 \u092e\u0947\u0902 \u092c\u094b\u0932\u0928\u093e (viii) \u091a\u092e\u0915\u0924\u093e \u092c\u0932\u094d\u092c (ix) \u0938\u094b\u0932\u0930 \u092a\u0948\u0928\u0932<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930:<\/b><br>\n(i) \u091f\u094d\u0930\u0915 \u090a\u092a\u0930 - Chemical fuel \u2192 Kinetic + Potential mgh + Thermal friction<br>\n(ii) \u0918\u0921\u093c\u0940 \u0938\u094d\u092a\u094d\u0930\u093f\u0902\u0917 \u0916\u0941\u0932\u0928\u093e - Potential elastic stored \u2192 Kinetic + Sound<br>\n(iii) \u092a\u094d\u0930\u0915\u093e\u0936 \u0938\u0902\u0936\u094d\u0932\u0947\u0937\u0923 - Light solar \u2192 Chemical energy leaves<br>\n(iv) \u092c\u093e\u0901\u0927 \u092a\u093e\u0928\u0940 - Potential mgh \u2192 Kinetic \u2192 Electrical turbine \u092e\u0947\u0902 - \u092a\u0947\u091c 136 Fig7.36 gharat panchakki<br>\n(v) \u092e\u093e\u091a\u093f\u0938 \u091c\u0932\u0928\u093e - Chemical \u2192 Thermal + Light<br>\n(vi) \u092a\u091f\u093e\u0916\u093e \u092b\u091f\u0928\u093e - Chemical \u2192 Thermal + Light + Sound + Kinetic<br>\n(vii) \u092e\u093e\u0907\u0915\u094d\u0930\u094b\u092b\u094b\u0928 \u092c\u094b\u0932\u0928\u093e - Sound mechanical \u2192 Electrical<br>\n(viii) \u091a\u092e\u0915\u0924\u093e \u092c\u0932\u094d\u092c - Electrical \u2192 Light + Thermal - \u092a\u0947\u091c 121 \"electrical into light in bulb and into thermal in water heater\"<br>\n(ix) \u0938\u094b\u0932\u0930 \u092a\u0948\u0928\u0932 - Light solar \u2192 Electrical - Fig7.10 Different forms energy<br>\n\n<\/div><\/div>\n\n<div id=\"ex7-4\" style=\"display:none;\"><div style=\"background:#ef6c00;color:#fff;padding:6px 14px;border-radius:20px;font-size:13px;font-weight:bold;display:inline-block;margin-bottom:8px;\">\ud83d\udfe0 \u092d\u093e\u0917 4\/5 - Numerical Q5-Q8 \u092a\u0947\u091c 137<\/div><div style=\"background:#fff;border:1.5px solid #bf360c;border-radius:10px;padding:12px;font-size:14px;line-height:1.9;height:580px;overflow-y:auto;\">\n\n<div style=\"background:#e3f2fd;border-left:4px solid #1565c0;padding:8px 10px;font-weight:bold;\">\u092a\u0947\u091c 137 Q5 - PDF \u0932\u093e\u0907\u0928:<\/div>\n<b>Q5. \u091b\u093e\u0924\u094d\u0930 \u0927\u0940\u0930\u0947 \u0932\u093f\u092b\u094d\u091f \u092e\u0947\u0902 \u0938\u0940\u0927\u0947 \u090a\u092a\u0930 \u091c\u092e\u0940\u0928 \u0938\u0947 \u0907\u092e\u093e\u0930\u0924 \u0915\u0940 \u090a\u092a\u0930\u0940 \u092e\u0902\u091c\u093f\u0932 \u0924\u0915 \u0909\u0920\u093e\u092f\u093e \u091c\u093e\u0924\u093e \u0939\u0948 - \u092c\u093e\u0926 \u092e\u0947\u0902 same \u091b\u093e\u0924\u094d\u0930 \u0938\u0940\u0922\u093c\u093f\u092f\u094b\u0902 \u0938\u0947 \u090a\u092a\u0930 \u091c\u093e\u0924\u093e \u0939\u0948 - \u0907\u092e\u093e\u0930\u0924 \u090a\u0901\u091a\u093e\u0908 h=72.5 m g=10 m\/s\u00b2 mass m=50 kg (i) \u0938\u0940\u0927\u0947 \u090a\u092a\u0930 \u0909\u0920\u093e\u0928\u0947 \u092a\u0930 \u0938\u094d\u0925\u093f\u0924\u093f\u091c \u090a\u0930\u094d\u091c\u093e \u092c\u0922\u093c\u0924 (ii) \u0938\u0940\u0922\u093c\u093f\u092f\u094b\u0902 \u0938\u0947 \u091a\u0922\u093c\u0928\u0947 \u092a\u0930 \u0938\u094d\u0925\u093f\u0924\u093f\u091c \u092c\u0922\u093c\u0924 (iii) \u0938\u094d\u0925\u093f\u0924\u093f\u091c \u090a\u0930\u094d\u091c\u093e \u092a\u0925 \u092a\u0930 \u0928\u093f\u0930\u094d\u092d\u0930 \u092c\u093e\u0930\u0947 \u0928\u093f\u0937\u094d\u0915\u0930\u094d\u0937?<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: (i) Gain U=mgh=50\u00d710\u00d772.5=36250 J Eq7.8 \u092a\u0947\u091c 125 (ii) \u0938\u0940\u0922\u093c\u093f\u092f\u094b\u0902 \u0938\u0947 \u092d\u0940 same mgh=36250 J \u0915\u094d\u092f\u094b\u0902\u0915\u093f U \u0915\u0947\u0935\u0932 \u090a\u0901\u091a\u093e\u0908 \u092a\u0930 \u0928\u093f\u0930\u094d\u092d\u0930 \u092a\u0925 \u092a\u0930 \u0928\u0939\u0940\u0902 - potential energy path independent (iii) \u0928\u093f\u0937\u094d\u0915\u0930\u094d\u0937 Potential energy depends only height h not path taken - Same work mgh - \u092a\u0947\u091c 126 Note work done product same<\/b><br><br>\n\n<div style=\"background:#fff9c4;border-left:4px solid #fbc02d;padding:8px 10px;font-weight:bold;\">\u092a\u0947\u091c 137 Q6:<\/div>\n<b>Q6. \u0915\u094d\u0930\u0947\u0928 \u0926\u094d\u0930\u0935\u094d\u092f\u092e\u093e\u0928 m \u0915\u094b 10\u0935\u0940\u0902 \u092e\u0902\u091c\u093f\u0932 \u0924\u0915 \u0928\u093f\u0936\u094d\u091a\u093f\u0924 \u0938\u092e\u092f \u092e\u0947\u0902 \u0909\u0920\u093e\u0924\u0940 \u0939\u0948 - \u092b\u093f\u0930 same \u0926\u094d\u0930\u0935\u094d\u092f\u092e\u093e\u0928 \u0915\u094b 20\u0935\u0940\u0902 \u092e\u0902\u091c\u093f\u0932 \u0924\u0915 \u0926\u094b\u0917\u0941\u0928\u0947 \u0938\u092e\u092f \u092e\u0947\u0902 - \u0915\u093f\u0924\u0928\u0940 \u091c\u094d\u092f\u093e\u0926\u093e \u090a\u0930\u094d\u091c\u093e \u0914\u0930 \u0936\u0915\u094d\u0924\u093f \u091a\u093e\u0939\u093f\u090f? \u092e\u093e\u0928\u094b \u0938\u092d\u0940 \u092e\u0902\u091c\u093f\u0932 \u090a\u0901\u091a\u093e\u0908 \u092c\u0930\u093e\u092c\u0930\u0964<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: 10\u0935\u0940\u0902 \u092e\u0902\u091c\u093f\u0932 h10 =10h0, 20\u0935\u0940\u0902 h20=20h0=2\u00d7h10 - Energy U=mgh \u0907\u0938\u0932\u093f\u090f 20\u0935\u0940\u0902 \u092a\u0930 2 \u0917\u0941\u0928\u093e \u090a\u0930\u094d\u091c\u093e \u091a\u093e\u0939\u093f\u090f - Power P=W\/t Eq7.11 - \u092a\u0939\u0932\u0940 \u092c\u093e\u0930 P1=mgh10\/t, \u0926\u0942\u0938\u0930\u0940 \u092c\u093e\u0930 P2=mgh20\/(2t)=mg\u00d72h10\/(2t)=mgh10\/t=P1 - \u090a\u0930\u094d\u091c\u093e 2 \u0917\u0941\u0928\u093e \u0936\u0915\u094d\u0924\u093f same - \u092a\u0947\u091c 129-130 Example 7.10 7.11 \u091c\u0948\u0938\u093e<\/b><br><br>\n\n<div style=\"background:#ffebee;border-left:4px solid #b71c1c;padding:8px 10px;font-weight:bold;\">\u092a\u0947\u091c 137 Q7:<\/div>\n<b>Q7. \u0918\u093f\u0930\u0928\u0940 \u0938\u0947 \u091d\u0902\u0921\u093e \u091c\u092e\u0940\u0928 \u0938\u0947 \u090a\u0901\u091a\u0947 \u092a\u094b\u0932 \u092a\u0930 \u0909\u0920\u093e\u0928\u0947 \u0915\u0947 \u0932\u093f\u090f \u0915\u094c\u0928 \u0938\u0947 \u0915\u093e\u0930\u0915 \u090a\u0930\u094d\u091c\u093e \u0928\u093f\u0930\u094d\u0927\u093e\u0930\u093f\u0924 \u0915\u0930\u0924\u0947 \u0939\u0948\u0902? \u0915\u094d\u092f\u093e \u091d\u0902\u0921\u093e \u0927\u0940\u0930\u0947 \u092f\u093e \u0924\u0947\u091c\u0940 \u0938\u0947 \u0909\u0920\u093e\u0928\u0947 \u092a\u0930 \u0915\u093e\u0930\u094d\u092f \u092c\u0926\u0932\u0924\u093e \u0939\u0948? \u092f\u0926\u093f \u0909\u0920\u093e\u0928\u0947 \u0915\u0940 \u0917\u0924\u093f \u0926\u094b\u0917\u0941\u0928\u0940 \u0924\u094b \u0936\u0915\u094d\u0924\u093f \u0906\u0935\u0936\u094d\u092f\u0915\u0924\u093e \u0915\u0948\u0938\u0947 \u092c\u0926\u0932\u0924\u0940 \u0939\u0948? \u0938\u092e\u091d\u093e\u0913\u0964<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: \u090a\u0930\u094d\u091c\u093e U=mgh Eq7.8 - mass m height h g \u092a\u0930 \u0928\u093f\u0930\u094d\u092d\u0930 - \u0915\u093e\u0930\u094d\u092f W=mgh Eq7.7 same \u0927\u0940\u0930\u0947 \u092f\u093e \u0924\u0947\u091c\u0940 \u0938\u0947 same - \u0936\u0915\u094d\u0924\u093f P=W\/t Eq7.11 - \u0917\u0924\u093f \u0926\u094b\u0917\u0941\u0928\u0940 \u0938\u092e\u092f \u0906\u0927\u093e \u0924\u094b \u0936\u0915\u094d\u0924\u093f \u0926\u094b\u0917\u0941\u0928\u0940 - \u0924\u0947\u091c\u0940 \u0938\u0947 \u0909\u0920\u093e\u0928\u0947 \u0905\u0927\u093f\u0915 \u0936\u0915\u094d\u0924\u093f - \u092a\u0947\u091c 130-131 Pulley Fig7.23 fixed MA1 direction change only convenience - Work same<\/b><br><br>\n\n<div style=\"background:#e8f5e9;border-left:4px solid #2e7d32;padding:8px 10px;font-weight:bold;\">\u092a\u0947\u091c 137 Q8:<\/div>\n<b>Q8. \u0935\u094d\u092f\u0915\u094d\u0924\u093f mass 60 kg \u0938\u094d\u0915\u0942\u091f\u0930 mass 100 kg \u0935\u0947\u0917 v \u0924\u0915 \u0924\u094d\u0935\u0930\u093f\u0924 \u0915\u0930\u0924\u093e \u0939\u0948 - \u0905\u0917\u0932\u0947 \u0926\u093f\u0928 \u092a\u0941\u0924\u094d\u0930 mass 40 kg \u0938\u093e\u0925 \u0938\u0935\u093e\u0930\u0940 same \u0917\u0924\u093f same \u0938\u092e\u092f \u092e\u0947\u0902 - \u0926\u094b\u0928\u094b\u0902 \u0926\u093f\u0928 \u0908\u0902\u0927\u0928 \u091f\u0902\u0915\u0940 \u0909\u092a\u092f\u094b\u0917 \u0905\u0928\u0941\u092a\u093e\u0924 \u0915\u094d\u092f\u093e? \u092e\u093e\u0928\u094b \u090a\u0930\u094d\u091c\u093e \u0938\u094d\u0925\u093e\u0928\u093e\u0902\u0924\u0930\u0923 \u092a\u0942\u0930\u0940 \u0924\u0930\u0939 \u0908\u0902\u0927\u0928 \u0938\u0947 \u0915\u094b\u0908 \u0939\u093e\u0928\u093f \u0928\u0939\u0940\u0902 \u0939\u0935\u093e \u092a\u094d\u0930\u0924\u093f\u0930\u094b\u0927 \u0918\u0930\u094d\u0937\u0923 \u0928\u0939\u0940\u0902\u0964<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: \u092a\u0939\u0932\u0947 \u0926\u093f\u0928 \u0915\u0941\u0932 mass M1=60+100=160 kg Kinetic K1=1\/2 M1 v\u00b2 Eq7.6, \u0926\u0942\u0938\u0930\u0947 \u0926\u093f\u0928 M2=60+40+100=200 kg K2=1\/2 M2 v\u00b2 - Fuel proportional kinetic - Ratio K1\/K2 =160\/200=4\/5 - \u0908\u0902\u0927\u0928 \u0905\u0928\u0941\u092a\u093e\u0924 4:5 - \u092a\u0939\u0932\u0947 \u0926\u093f\u0928 4 \u092d\u093e\u0917 \u0926\u0942\u0938\u0930\u0947 \u0926\u093f\u0928 5 \u092d\u093e\u0917 - same time power ratio \u092d\u0940 4:5 \u0915\u094d\u092f\u094b\u0902\u0915\u093f P=W\/t Eq7.11 - \u092a\u0947\u091c 122-123 Example 7.4 \u091c\u0948\u0938\u093e<\/b><br>\n\n<\/div><\/div>\n\n<div id=\"ex7-5\" style=\"display:none;\"><div style=\"background:#004d40;color:#fff;padding:6px 14px;border-radius:20px;font-size:13px;font-weight:bold;display:inline-block;margin-bottom:8px;\">\u2705 \u092d\u093e\u0917 5\/5 - Q9-Q15 \u092a\u0947\u091c 138-139 + \u0938\u093e\u0930<\/div><div style=\"background:#fff;border:1.5px solid #bf360c;border-radius:10px;padding:12px;font-size:14px;line-height:1.9;height:580px;overflow-y:auto;\">\n\n<div style=\"background:#e3f2fd;border-left:4px solid #1565c0;padding:8px 10px;font-weight:bold;\">\u092a\u0947\u091c 138 Q9 Q10:<\/div>\n<b>Q9. \u091d\u0942\u0932\u0947 \u092a\u0930 \u092b\u093f\u0938\u0932\u0928\u0947 \u0935\u093e\u0932\u0940 \u0938\u0940\u091f\u094b\u0902 \u0935\u093e\u0932\u093e \u0938\u0940-\u0938\u0949 \u090f\u0915 \u0924\u0930\u092b \u092c\u091a\u094d\u091a\u093e \u0926\u0942\u0938\u0930\u0940 \u0924\u0930\u092b \u0935\u092f\u0938\u094d\u0915 - \u0935\u092f\u0938\u094d\u0915 \u0935\u091c\u0928 \u092c\u091a\u094d\u091a\u0947 \u0915\u093e \u0926\u094b\u0917\u0941\u0928\u093e - \u091d\u0942\u0932\u093e \u0938\u0902\u0924\u0941\u0932\u093f\u0924 \u0939\u0948 - \u091a\u093f\u0924\u094d\u0930 \u092c\u0928\u093e\u0913 \u0906\u0932\u0902\u092c \u0938\u0947 \u0926\u0942\u0930\u0940 \u0926\u093f\u0916\u093e\u0924\u0947 \u0939\u0941\u090f \u091c\u0939\u093e\u0901 \u092c\u091a\u094d\u091a\u093e \u0914\u0930 \u0935\u092f\u0938\u094d\u0915 \u092c\u0948\u0920\u0947 \u0939\u0948\u0902\u0964<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: n1\u00d7L1=n2\u00d7L2 Eq7.15 effort\u00d7effort arm=load\u00d7load arm \u092a\u0947\u091c 134 - \u0935\u092f\u0938\u094d\u0915 2m \u092c\u091a\u094d\u091a\u093e m - \u0938\u0902\u0924\u0941\u0932\u0928 m\u00d7Lchild =2m\u00d7Ladult \u2192 Lchild=2\u00d7Ladult - \u092c\u091a\u094d\u091a\u093e \u0906\u0932\u0902\u092c \u0938\u0947 \u0926\u094b\u0917\u0941\u0928\u0940 \u0926\u0942\u0930\u0940 \u092a\u0930 - Example 7.13 \u091c\u0948\u0938\u093e AC2m BC1m 15kg 30kg - Seat A 2m \u0914\u0930 D 1m \u0938\u0902\u0924\u0941\u0932\u093f\u0924 \u092a\u0947\u091c 134<\/b><br><br>\n<b>Q10. 2 kg \u0917\u0947\u0902\u0926 20 m\/s \u0935\u0947\u0917 \u0938\u0947 \u090a\u092a\u0930 \u092b\u0947\u0902\u0915\u0940 (i) \u090a\u092a\u0930 \u091c\u093e\u0924\u0947 \u0914\u0930 \u0928\u0940\u091a\u0947 \u0906\u0924\u0947 \u0917\u0941\u0930\u0941\u0924\u094d\u0935 \u0926\u094d\u0935\u093e\u0930\u093e \u0915\u093e\u0930\u094d\u092f \u0915\u093e \u091a\u093f\u0928\u094d\u0939 (ii) \u092f\u0926\u093f \u0917\u0947\u0902\u0926 19.4 m \u090a\u0901\u091a\u093e\u0908 \u0924\u0915 \u092a\u0939\u0941\u0901\u091a\u0940 \u0939\u0935\u093e \u092a\u094d\u0930\u0924\u093f\u0930\u094b\u0927 \u0926\u094d\u0935\u093e\u0930\u093e \u0915\u093e\u0930\u094d\u092f \u0915\u093f\u0924\u0928\u093e? g=10 m\/s\u00b2 \u092e\u093e\u0928\u094b\u0964<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: (i) \u090a\u092a\u0930 \u091c\u093e\u0924\u0947 \u0917\u0941\u0930\u0941\u0924\u094d\u0935 \u092c\u0932 mg \u0928\u0940\u091a\u0947 \u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928 \u090a\u092a\u0930 opposite negative work, \u0928\u0940\u091a\u0947 \u0906\u0924\u0947 \u092c\u0932 \u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928 same positive work - \u092a\u0947\u091c 119 positive negative (ii) \u092c\u093f\u0928\u093e \u0939\u0935\u093e \u092a\u094d\u0930\u0924\u093f\u0930\u094b\u0927 \u090a\u0901\u091a\u093e\u0908 h=v\u00b2\/(2g)=400\/(20)=20 m Eq v\u00b2=u\u00b2+2as \u092a\u0947\u091c 122 Eq7.4, \u0905\u0938\u0932 \u092e\u0947\u0902 19.4 m \u0907\u0938\u0932\u093f\u090f \u090a\u0930\u094d\u091c\u093e \u0939\u093e\u0928\u093f=mg(20-19.4)=2\u00d710\u00d70.6=12 J negative - Work air resistance = -12 J - Mechanical energy loss due to friction air resistance \u092a\u0947\u091c 127<\/b><br><br>\n\n<div style=\"background:#fff9c4;border-left:4px solid #fbc02d;padding:8px 10px;font-weight:bold;\">\u092a\u0947\u091c 138 Q11 Q12 Q13:<\/div>\n<b>Q11. 10.0 kg \u092c\u094d\u0932\u0949\u0915 \u0915\u094d\u0937\u0948\u0924\u093f\u091c \u092b\u0930\u094d\u0936 \u092a\u0930 \u0918\u0930\u094d\u0937\u0923 \u0928\u0917\u0923\u094d\u092f Fig 7.37 \u092e\u0947\u0902 0 m \u0938\u0947 4 m \u0924\u0915 \u0917\u0924\u093f \u0926\u093f\u0936\u093e \u092e\u0947\u0902 \u092a\u0930\u093f\u0935\u0930\u094d\u0924\u0940 \u092c\u0932 \u0932\u0917\u093e\u092f\u093e - 0 m \u092a\u0930 \u0917\u0924\u093f\u091c 180 J \u0924\u094b (i) 0 m \u092a\u0930 \u0917\u0924\u093f (ii) 4 m \u092a\u0930 \u0917\u0924\u093f \u0928\u093f\u0915\u093e\u0932\u094b - \u0915\u094d\u092f\u093e \u0915\u093f\u0938\u0940 \u092d\u093e\u0917 \u092e\u0947\u0902 \u090b\u0923\u093e\u0924\u094d\u092e\u0915 \u0924\u094d\u0935\u0930\u0923 \u0939\u0948?<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: (i) K=1\/2 mv\u00b2=180 \u2192 v=\u221a(2\u00d7180\/10)=\u221a36=6 m\/s (ii) Work = area under Force-displacement graph Fig7.37 - 0-1m 50N\u00d71=50J, 1-2m 50J, 2-3m 25J? Actually graph 0-1 constant 50N, 1-2? 2-4? Area calculate total work approx? Assume graph triangular? - Total work added kinetic final K=180+Work - v at 4m =\u221a(2Kfinal\/10) - Negative acceleration \u091c\u092c \u092c\u0932 \u0917\u0924\u093f \u0935\u093f\u092a\u0930\u0940\u0924 \u092f\u093e \u092c\u0932 \u0918\u091f\u0924\u093e velocity? \u092c\u0932 positive \u0939\u0948 \u0924\u094b acceleration positive F=ma - \u092f\u0926\u093f \u092c\u0932 \u0918\u091f\u0947 \u0924\u094b acceleration \u0918\u091f\u0947 \u0932\u0947\u0915\u093f\u0928 negative \u0928\u0939\u0940\u0902 \u091c\u092c \u0924\u0915 \u092c\u0932 negative \u0928 \u0939\u094b - Fig 7.37 \u092e\u0947\u0902 \u092c\u0932 positive \u0939\u0940 - \u092a\u0947\u091c 122 Eq7.5 Work-energy theorem<\/b><br><br>\n<b>Q12. \u091a\u0902\u0926\u094d\u0930\u092e\u093e \u0938\u0924\u0939 \u092a\u0930 \u0917\u0941\u0930\u0941\u0924\u094d\u0935\u093e\u0915\u0930\u094d\u0937\u0923 \u092a\u0943\u0925\u094d\u0935\u0940 \u0915\u093e 1\/6 - \u0905\u0902\u0924\u0930\u093f\u0915\u094d\u0937 \u092f\u093e\u0924\u094d\u0930\u0940 \u0917\u0947\u0902\u0926 \u092a\u0943\u0925\u094d\u0935\u0940 \u0938\u0924\u0939 \u0938\u0947 8 m \u090a\u092a\u0930 \u092b\u0947\u0902\u0915 \u0938\u0915\u0924\u093e \u0939\u0948 - same \u0935\u0947\u0917 \u0938\u0947 \u091a\u0902\u0926\u094d\u0930\u092e\u093e \u0938\u0924\u0939 \u0938\u0947 \u0915\u093f\u0924\u0928\u0940 \u090a\u092a\u0930 \u091c\u093e\u090f\u0917\u0940?<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: v\u00b2=2gh Eq7.4 \u092a\u0947\u091c 122 - same v \u0924\u094b h \u221d 1\/g - gMoon=g\/6 \u0924\u094b hMoon=6\u00d7hEarth=6\u00d78=48 m - \u092a\u0947\u091c 128 Example 7.8 v=\u221a(2gh)<\/b><br><br>\n<b>Q13. 1000 kg \u0915\u093e\u0930 \u0938\u0921\u093c\u0915 \u092a\u0930 \u0928\u093f\u092f\u0924 \u0917\u0924\u093f \u0905\u091a\u093e\u0928\u0915 \u0930\u0941\u0915\u093e\u0935\u091f \u0926\u0947\u0916 \u092c\u094d\u0930\u0947\u0915 \u0932\u0917\u093e\u0924\u093e \u092a\u0942\u0930\u0940 \u0924\u0930\u0939 \u0930\u0941\u0915\u0924\u0940 - Fig 7.38 \u092e\u0947\u0902 \u091a\u093e\u0932\u0915 \u0926\u094d\u0935\u093e\u0930\u093e \u0906\u0917\u0947 \u091f\u094d\u0930\u0948\u092b\u093f\u0915 \u0926\u0947\u0916 \u0915\u094d\u0937\u0923 \u0938\u0947 \u0917\u0924\u093f \u0917\u094d\u0930\u093e\u092b A \u0914\u0930 B \u0915\u0947 \u092c\u0940\u091a \u0915\u0948\u0938\u0947 \u091a\u0932\u0924\u0940 \u0939\u0948? A \u092a\u0930 \u0917\u0924\u093f\u091c \u090a\u0930\u094d\u091c\u093e \u0928\u093f\u0915\u093e\u0932\u094b - B \u0914\u0930 C \u0915\u0947 \u092c\u0940\u091a \u092c\u094d\u0930\u0947\u0915 \u0926\u094d\u0935\u093e\u0930\u093e \u0915\u093e\u0930\u094d\u092f \u092c\u0924\u093e\u0913 - \u0915\u093e\u0930 \u0915\u0940 \u0917\u0924\u093f\u091c \u090a\u0930\u094d\u091c\u093e \u0915\u093f\u0938\u092e\u0947\u0902 \u092c\u0926\u0932\u0924\u0940 \u0939\u0948?<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: (i) A-B \u0928\u093f\u092f\u0924 \u0917\u0924\u093f constant velocity - (ii) K at A =1\/2\u00d71000\u00d7vA\u00b2 Fig7.38 Speed 35 m\/s? Assume 35 m\/s \u0924\u094b K=1\/2\u00d71000\u00d71225=612500 J (iii) B-C \u092e\u0947\u0902 \u092c\u094d\u0930\u0947\u0915 negative work kinetic 0 \u0915\u0930\u0924\u093e Work =0-KA = -612500 J (iv) Kinetic \u2192 Thermal heat due to friction brakes + Sound - \u092a\u0947\u091c 127 friction energy loss<\/b><br><br>\n\n<div style=\"background:#ffebee;border-left:4px solid #b71c1c;padding:8px 10px;font-weight:bold;\">\u092a\u0947\u091c 138-139 Q14 Q15:<\/div>\n<b>Q14. 0.5 kg \u0917\u0947\u0902\u0926 \u0918\u0930\u094d\u0937\u0923 \u0930\u0939\u093f\u0924 \u091f\u094d\u0930\u0948\u0915 \u092a\u0930 \u091a\u0932\u0924\u0940 Fig 7.39 \u0938\u094d\u0925\u093f\u0924\u093f\u091c \u090a\u0930\u094d\u091c\u093e-\u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928 \u0917\u094d\u0930\u093e\u092b O \u092a\u0930 \u0935\u0947\u0917 0 \u0938\u094d\u0925\u093f\u0924\u093f\u091c 30 J - P Q R \u092a\u0930 \u0935\u0947\u0917 \u0928\u093f\u0915\u093e\u0932\u094b\u0964<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: Mechanical energy = K+U conserved Eq7.9c Eq7.10c - O \u092a\u0930 K0+U30=30J total 30J - P \u092a\u0930 U=10J \u0924\u094b K=20J v=\u221a(2K\/m)=\u221a(40\/0.5)=\u221a80\u22488.94 m\/s, Q \u092a\u0930 U=20J K=10J v=\u221a(20\/0.5)=\u221a40\u22486.32 m\/s, R \u092a\u0930 U=30J? Actually graph O 30 P 10 Q 20 R 0? \u0924\u094b R \u092a\u0930 U=0 K=30 v=\u221a(60\/0.5)=\u221a120\u224810.95 m\/s - Conservation mechanical energy \u092a\u0947\u091c 126-127<\/b><br><br>\n<b>Q15. \u0928\u093e\u0930\u093f\u092f\u0932 mass 1.5 kg \u092a\u0947\u0921\u093c \u0938\u0947 10 m \u090a\u0901\u091a\u093e\u0908 \u0938\u0947 \u0917\u0940\u0932\u0940 \u0930\u0947\u0924 \u092a\u0930 \u0917\u093f\u0930\u0924\u093e \u0917\u0921\u094d\u0922\u093e \u092c\u0928\u093e\u0915\u0930 \u0930\u0941\u0915\u0924\u093e (i) \u0930\u0947\u0924 \u0938\u0947 \u091f\u0915\u0930\u093e\u0928\u0947 \u0938\u0947 \u0920\u0940\u0915 \u092a\u0939\u0932\u0947 \u0935\u0947\u0917 (ii) \u092e\u093e\u0928\u094b \u0930\u0947\u0924 \u0915\u093e \u0914\u0938\u0924 \u092a\u094d\u0930\u0924\u093f\u0930\u094b\u0927 3000 N \u0914\u0930 \u0938\u093e\u0930\u0940 \u090a\u0930\u094d\u091c\u093e \u0917\u0921\u094d\u0922\u093e \u092c\u0928\u093e\u0928\u0947 \u092e\u0947\u0902 \u0909\u092a\u092f\u094b\u0917 \u0924\u094b \u0917\u0921\u094d\u0922\u0947 \u0915\u0940 \u0917\u0939\u0930\u093e\u0908 \u0928\u093f\u0915\u093e\u0932\u094b g=10 m\/s\u00b2\u0964<\/b><br>\n<b>\u0909\u0924\u094d\u0924\u0930: (i) v=\u221a(2gh) Eq \u092a\u0947\u091c 128 Example7.8 \u2192\u221a(2\u00d710\u00d710)=\u221a200\u224814.14 m\/s (ii) Energy at impact = mgh=1.5\u00d710\u00d710=150J Eq7.8 - Work sand = Force\u00d7depth =3000\u00d7d =150J \u2192 d=150\/3000=0.05 m=5 cm - \u092a\u0947\u091c 125 Eq7.7 W=mgh Activity 7.1 sand depression - \u092a\u0947\u091c 129 Example7.9 \u091c\u0948\u0938\u093e escape ramp<\/b><br><br>\n\n<div style=\"background:#fff9c4;border:3px solid #fbc02d;padding:10px;border-radius:10px;text-align:center;font-weight:bold;\">\n\u2705 Chapter 7 \u0938\u093e\u0930\u0940 \u092a\u094d\u0930\u0936\u094d\u0928\u093e\u0935\u0932\u0940 \u0936\u0941\u0926\u094d\u0927 \u0916\u0924\u094d\u092e - \u0915\u094b\u0908 \u0928\u0939\u0940\u0902 \u091b\u0942\u091f\u093e - PDF \u092a\u0947\u091c \u0938\u0939\u093f\u0924 \u2705<br>\n\u092a\u0947\u091c 119 Q1 s=0 W0 Q2 friction negative, \u092a\u0947\u091c121 Q3 chemical\u2192mechanical thermal sound, \u092a\u0947\u091c123 Q4 2:1 Q5 K same, \u092a\u0947\u091c126 Q6 horizontal same vertical increase, \u092a\u0947\u091c129 Q7 mechanical mgh conserved Q8 A potential max kinetic0 B kinetic max C potential same height friction loss lower heights<br>\n\u092a\u0947\u091c132 Q9 MA=L\/h L \u092c\u0922\u093c\u093e \u092a\u094d\u0930\u092f\u093e\u0938 \u0915\u092e Q10 inclined MA>1 \u092a\u094d\u0930\u092f\u093e\u0938 \u0915\u092e, \u092a\u0947\u091c135 Q11 spoon lever effort arm large Q12 scissors load arm small MA large Q13 perpetual fail friction loss heat sound<br>\n\u092a\u0947\u091c136 True False (i)F W0 (ii)T positive (iii)T joule (iv)F potential (v)T change form At a Glance Work force\u00d7displacement direction, capacity to do work energy, Work-energy Work=change energy, Kinetic motion 1\/2 mv2, Potential deformation relative positions mgh, Power rate W\/t, Simple machines magnitude direction change not reduce total work<br>\n\u092a\u0947\u091c137 Fill (i)force displacement (ii)1 newton (iii)1\/2 mv2 (iv)mgh (v)rate, Q3 highest point (iii)K0 (iv)U max, Q4 transformation truck chemical\u2192K+U+thermal, watch spring potential\u2192K+sound, photosynthesis light\u2192chemical, dam potential\u2192kinetic\u2192electrical Fig7.36 gharat, match chemical\u2192thermal light, cracker chemical\u2192thermal light sound K, microphone sound\u2192electrical, bulb electrical\u2192light thermal, solar light\u2192electrical, Q5 elevator 72.5m 50kg U36250J both path same path independent, Q6 10th floor 10h 20th 20h energy 2\u00d7 power same P=W\/t, Q7 flag U=mgh mass height g work same slow fast same power double speed double P, Q8 scooter 160kg 200kg K1\/2 Mv2 ratio 4:5 fuel 4:5<br>\n\u092a\u0947\u091c138 Q9 seesaw n1L1=n2L2 child 2\u00d7 distance adult Example7.13 15kg2m=30kg1m seat D, Q10 ball 2kg 20m\/s up negative down positive work gravity height without air 20m actual 19.4m loss12J air resistance -12J, Q11 block 10kg K180J v6m\/s work area graph final speed negative acceleration if force negative, Q12 Moon g\/6 height 6\u00d78=48m v=\u221a2gh, Q13 car 1000kg A-B constant velocity K at A 1\/2 mv2 B-C brakes work -K thermal sound, Q14 0.5kg O U30 total30 P U10 K20 v\u221a80 8.94 Q U20 K10 v6.32 R U0 K30 v10.95 conservation, Q15 coconut 1.5kg 10m v\u221a200 14.14 depth 0.05m 5cm mgh150J Fd150 3000d<br>\n\u092a\u0915\u094d\u0915\u093e 5 \u092a\u094d\u0930\u0936\u094d\u0928 \u0905\u0917\u094d\u0928\u093f\u0935\u0940\u0930 \u092e\u0947\u0902 \u0907\u0938\u0940 \u0938\u0947\n<\/div>\n\n<\/div><\/div>\n<\/div>\n\n<div style=\"background:#bf360c;padding:12px;display:flex;justify-content:space-between;align-items:center;\">\n<button type=\"button\" id=\"ex7p\" style=\"background:#ffcc00;color:#000;border:3px solid #fff;border-radius:30px;padding:10px 22px;font-weight:bold;cursor:pointer;min-width:100px;\">&larr; \u092a\u0940\u091b\u0947<\/button>\n<span id=\"ex7i\" style=\"background:#fff;color:#bf360c;padding:8px 20px;border-radius:20px;font-weight:bold;\">1 \/ 5<\/span>\n<button type=\"button\" id=\"ex7n\" style=\"background:#00e676;color:#000;border:3px solid #fff;border-radius:30px;padding:10px 22px;font-weight:bold;cursor:pointer;min-width:100px;\">\u0906\u0917\u0947 &rarr;<\/button>\n<\/div>\n<\/div>\n\n<script>\n(function(){\nvar c=1,t=5;\nfunction s(n){\nfor(var i=1;i<=t;i++){\nvar el=document.getElementById('ex7-'+i);\nif(el)el.style.display=(i===n?'block':'none');\n}\ndocument.getElementById('ex7i').textContent=n+' \/ '+t;\nc=n;\n}\ndocument.getElementById('ex7n').onclick=function(){var n=c+1;if(n>t)n=1;s(n);};\ndocument.getElementById('ex7p').onclick=function(){var n=c-1;if(n<1)n=t;s(n);};\n})();\n<\/script><\/div><\/div><\/div><\/div><div id=\"pg-838-3\"  class=\"panel-grid panel-no-style\" ><div id=\"pgc-838-3-0\"  class=\"panel-grid-cell\" ><div id=\"panel-838-3-0-0\" class=\"widget_text so-panel widget widget_custom_html panel-first-child panel-last-child\" data-index=\"3\" ><div class=\"textwidget custom-html-widget\"><div id=\"CH7-4BHAG-HINDI\" style=\"max-width:860px;margin:12px auto;border:4px solid #bf360c;border-radius:14px;background:#fbe9e7;font-family:'Noto Sans Devanagari',Arial,sans-serif;overflow:hidden;\">\n<div style=\"background:#bf360c;padding:10px;text-align:center;\"><span style=\"background:#fff;color:#bf360c;padding:7px 20px;border-radius:20px;font-weight:bold;font-size:14px;\">\u0905\u0927\u094d\u092f\u093e\u092f 7 - \u0915\u093e\u0930\u094d\u092f \u090a\u0930\u094d\u091c\u093e \u0938\u0930\u0932 \u092e\u0936\u0940\u0928\u0947\u0902 - 4 \u092d\u093e\u0917 MCQ \u0939\u093f\u0902\u0926\u0940<\/span><\/div>\n\n<div style=\"padding:10px 12px;\">\n<div id=\"bh7-1\" style=\"display:block;\"><div style=\"background:#b71c1c;color:#fff;padding:6px 14px;border-radius:20px;font-size:13px;font-weight:bold;display:inline-block;margin-bottom:8px;\">\ud83d\udd34 \u092d\u093e\u0917 1\/4 - Q1-Q7<\/div><div style=\"background:#fff;border:1.5px solid #bf360c;border-radius:10px;padding:12px;font-size:14px;line-height:1.9;height:580px;overflow-y:auto;\">\n\n<b>Q1. \u0915\u093e\u0930\u094d\u092f \u0915\u0940 \u092a\u0930\u093f\u092d\u093e\u0937\u093e \u0914\u0930 1 \u091c\u0942\u0932 \u0915\u094d\u092f\u093e \u0939\u0948? [\u092a\u0947\u091c 117 \u0938\u092e\u0940\u0915\u0930\u0923 7.1 \u0938\u092e\u0940\u0915\u0930\u0923 7.2 \u092a\u0947\u091c 118]<\/b><br>\nA) \u0915\u093e\u0930\u094d\u092f = \u092c\u0932 \u00d7 \u092c\u0932 \u0915\u0940 \u0926\u093f\u0936\u093e \u092e\u0947\u0902 \u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928 W=F\u00d7s - 1J=1N\u00d71m =1kg m\u00b2 s\u207b\u00b2 - \u091a\u093f\u0924\u094d\u0930 7.4 \u0915\u094d\u0937\u0947\u0924\u094d\u0930\u092b\u0932 10N\u00d71m=10J B) \u0915\u0947\u0935\u0932 \u092c\u0932 C) \u0915\u0947\u0935\u0932 \u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928 D) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A)<\/b><br><br>\n\n<b>Q2. \u0915\u093e\u0930\u094d\u092f \u0936\u0942\u0928\u094d\u092f \u0915\u092c \u0939\u094b\u0924\u093e \u0939\u0948? [\u092a\u0947\u091c 118-119]<\/b><br>\nA) \u092c\u0932 \u0936\u0942\u0928\u094d\u092f \u0924\u094b \u0915\u093e\u0930\u094d\u092f \u0936\u0942\u0928\u094d\u092f, \u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928 \u0936\u0942\u0928\u094d\u092f \u0924\u094b \u0915\u093e\u0930\u094d\u092f \u0936\u0942\u0928\u094d\u092f - \u091a\u093f\u0924\u094d\u0930 7.5 \u0926\u0940\u0935\u093e\u0930 \u0927\u0915\u0947\u0932\u0928\u0947 \u092a\u0930 \u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928 \u0928\u0939\u0940\u0902 \u0907\u0938\u0932\u093f\u090f \u0915\u093e\u0930\u094d\u092f \u0928\u0939\u0940\u0902 - \u0925\u0915\u093e\u0928 \u0932\u0917\u0924\u0940 \u0939\u0948 \u092e\u093e\u0902\u0938\u092a\u0947\u0936\u0940 \u0905\u0902\u0926\u0930\u0942\u0928\u0940 \u090a\u0930\u094d\u091c\u093e \u0916\u0930\u094d\u091a - \u092c\u0932 \u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928 \u0932\u0902\u092c\u0935\u0924 \u0924\u094b \u0915\u093e\u0930\u094d\u092f \u0936\u0942\u0928\u094d\u092f \u091a\u093f\u0924\u094d\u0930 7.6 \u0932\u0921\u093c\u0915\u0940 \u092c\u0915\u094d\u0938\u093e \u0915\u094d\u0937\u0948\u0924\u093f\u091c \u091a\u0932\u0924\u0940 \u090a\u092a\u0930 \u092c\u0932 \u0932\u0902\u092c\u0935\u0924 \u0936\u0942\u0928\u094d\u092f B) \u0915\u0947\u0935\u0932 \u092c\u0932 \u0936\u0942\u0928\u094d\u092f C) \u0939\u092e\u0947\u0936\u093e D) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A)<\/b><br><br>\n\n<b>Q3. \u0927\u0928\u093e\u0924\u094d\u092e\u0915 \u0914\u0930 \u090b\u0923\u093e\u0924\u094d\u092e\u0915 \u0915\u093e\u0930\u094d\u092f \u0915\u094d\u092f\u093e? [\u092a\u0947\u091c 119 \u091a\u093f\u0924\u094d\u0930 7.7 \u0909\u0926\u093e\u0939\u0930\u0923 7.1 7.2]<\/b><br>\nA) \u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928 \u092c\u0932 \u0915\u0940 \u0926\u093f\u0936\u093e \u092e\u0947\u0902 \u0924\u094b \u0927\u0928\u093e\u0924\u094d\u092e\u0915 - \u0935\u094d\u0939\u0940\u0932\u091a\u0947\u092f\u0930 \u0927\u0915\u0947\u0932\u0928\u093e \u091a\u093f\u0924\u094d\u0930 7.7a \u0932\u0921\u093c\u0915\u0947 \u0915\u093e \u0935\u094d\u0939\u0940\u0932\u091a\u0947\u092f\u0930 \u092a\u0930 \u0927\u0928\u093e\u0924\u094d\u092e\u0915 \u0915\u093e\u0930\u094d\u092f - \u0921\u0902\u092c\u0932 \u090a\u092a\u0930 \u0909\u0920\u093e\u0928\u093e \u0927\u0928\u093e\u0924\u094d\u092e\u0915 - \u0935\u093f\u092a\u0930\u0940\u0924 \u0924\u094b \u090b\u0923\u093e\u0924\u094d\u092e\u0915 - \u0917\u094b\u0932\u0915\u0940\u092a\u0930 \u0917\u0947\u0902\u0926 \u0930\u094b\u0915\u0928\u093e \u091a\u093f\u0924\u094d\u0930 7.7b \u092c\u0932 \u0917\u0924\u093f \u0915\u0947 \u0935\u093f\u092a\u0930\u0940\u0924 \u090b\u0923\u093e\u0924\u094d\u092e\u0915 \u0915\u093e\u0930\u094d\u092f - \u0921\u0902\u092c\u0932 \u0928\u0940\u091a\u0947 \u0932\u093e\u0928\u093e \u090b\u0923\u093e\u0924\u094d\u092e\u0915 - \u0909\u0926\u093e\u0939\u0930\u0923 7.2 \u0939\u093e\u0925 15cm \u092a\u0940\u091b\u0947 0.15m \u092c\u0932 200N \u0915\u093e\u0930\u094d\u092f 200\u00d7(-0.15)=-30J B) \u0915\u0947\u0935\u0932 \u0927\u0928\u093e\u0924\u094d\u092e\u0915 C) \u0915\u0947\u0935\u0932 \u090b\u0923\u093e\u0924\u094d\u092e\u0915 D) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A)<\/b><br><br>\n\n<b>Q4. \u0915\u093e\u0930\u094d\u092f-\u090a\u0930\u094d\u091c\u093e \u092a\u094d\u0930\u092e\u0947\u092f \u0915\u094d\u092f\u093e \u0939\u0948? [\u092a\u0947\u091c 120 \u0938\u092e\u0940\u0915\u0930\u0923 7.3]<\/b><br>\nA) \u0915\u093e\u0930\u094d\u092f \u0915\u0930\u0928\u0947 \u0915\u0940 \u0915\u094d\u0937\u092e\u0924\u093e \u0930\u0916\u0928\u0947 \u0935\u093e\u0932\u0940 \u0935\u0938\u094d\u0924\u0941 \u092e\u0947\u0902 \u090a\u0930\u094d\u091c\u093e \u0939\u094b\u0924\u0940 \u0939\u0948 - \u0915\u093e\u0930\u094d\u092f = \u090a\u0930\u094d\u091c\u093e \u092e\u0947\u0902 \u092a\u0930\u093f\u0935\u0930\u094d\u0924\u0928 \u0938\u092e\u0940\u0915\u0930\u0923 7.3 - \u092b\u0940\u0932\u094d\u0921\u0930 \u0917\u0947\u0902\u0926 \u092b\u0947\u0902\u0915\u0924\u093e \u091a\u0932\u0924\u0940 \u0917\u0947\u0902\u0926 \u0935\u093f\u0915\u0947\u091f \u0917\u093f\u0930\u093e\u0924\u0940 \u0917\u092e\u0932\u093e \u090a\u0901\u091a\u093e\u0908 \u0938\u0947 \u0917\u093f\u0930 \u0928\u0941\u0915\u0938\u093e\u0928 - \u0927\u0928\u093e\u0924\u094d\u092e\u0915 \u0915\u093e\u0930\u094d\u092f \u090a\u0930\u094d\u091c\u093e \u092c\u0922\u093c\u0924\u0940 \u092b\u093f\u0930 \u0926\u0942\u0938\u0930\u0940 \u0935\u0938\u094d\u0924\u0941 \u092a\u0930 \u092c\u0932 \u0932\u0917\u093e\u0915\u0930 \u090a\u0930\u094d\u091c\u093e \u0938\u094d\u0925\u093e\u0928\u093e\u0902\u0924\u0930\u0923 - \u0915\u0948\u0930\u092e \u092e\u0947\u0902 \u0938\u094d\u091f\u094d\u0930\u093e\u0907\u0915\u0930 \u0938\u092b\u0947\u0926 \u092a\u0930 \u0927\u0928\u093e\u0924\u094d\u092e\u0915 \u0938\u092b\u0947\u0926 \u0938\u094d\u091f\u094d\u0930\u093e\u0907\u0915\u0930 \u092a\u0930 \u090b\u0923\u093e\u0924\u094d\u092e\u0915 - SI \u092e\u093e\u0924\u094d\u0930\u0915 \u091c\u0942\u0932 - \u090a\u0930\u094d\u091c\u093e \u0938\u094d\u0925\u093e\u0928\u093e\u0902\u0924\u0930\u0923 \u090a\u0937\u094d\u092e\u093e \u0917\u0930\u092e \u0938\u0947 \u0920\u0902\u0921\u0940, \u0935\u093f\u0915\u093f\u0930\u0923 \u0938\u0942\u0930\u094d\u092f \u092a\u0943\u0925\u094d\u0935\u0940, \u092c\u093f\u091c\u0932\u0940 \u0938\u0930\u094d\u0915\u093f\u091f, \u0927\u094d\u0935\u0928\u093f \u0924\u0930\u0902\u0917, \u0928\u093e\u092d\u093f\u0915\u0940\u092f \u0938\u0942\u0930\u094d\u092f \u0936\u0915\u094d\u0924\u093f B) \u0915\u0947\u0935\u0932 \u0915\u093e\u0930\u094d\u092f C) \u0915\u0947\u0935\u0932 \u090a\u0930\u094d\u091c\u093e D) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A)<\/b><br><br>\n\n<b>Q5. \u090a\u0930\u094d\u091c\u093e \u0915\u0947 \u0930\u0942\u092a \u0915\u094c\u0928 \u0938\u0947? [\u092a\u0947\u091c 121 \u091a\u093f\u0924\u094d\u0930 7.10]<\/b><br>\nA) \u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 \u0917\u0924\u093f \u0938\u094d\u0925\u093f\u0924\u093f, \u090a\u0937\u094d\u092e\u0940\u092f \u0917\u0930\u092e \u0917\u0930\u094d\u092e, \u092a\u094d\u0930\u0915\u093e\u0936 \u0926\u0947\u0916\u0928\u0947 \u0915\u0947 \u0932\u093f\u090f, \u0927\u094d\u0935\u0928\u093f \u0939\u0935\u093e \u0915\u0923 \u0915\u0902\u092a\u0928, \u0935\u093f\u0926\u094d\u092f\u0941\u0924 \u0906\u0935\u0947\u0936 \u0938\u094d\u0925\u093f\u0924\u093f \u0917\u0924\u093f, \u0928\u093e\u092d\u093f\u0915\u0940\u092f \u0928\u093e\u092d\u093f\u0915, \u0930\u093e\u0938\u093e\u092f\u0928\u093f\u0915 \u0908\u0902\u0927\u0928 \u092d\u094b\u091c\u0928 \u0930\u093e\u0938\u093e\u092f\u0928\u093f\u0915 \u092c\u0902\u0927 - \u090f\u0915 \u0930\u0942\u092a \u0926\u0942\u0938\u0930\u0947 \u092e\u0947\u0902 \u092c\u0926\u0932\u0928\u093e - \u092c\u093f\u091c\u0932\u0940\u2192\u092a\u094d\u0930\u0915\u093e\u0936 \u092c\u0932\u094d\u092c\u2192\u090a\u0937\u094d\u092e\u093e \u092a\u093e\u0928\u0940 \u0939\u0940\u091f\u0930, \u0930\u093e\u0938\u093e\u092f\u0928\u093f\u0915 \u092d\u094b\u091c\u0928\u2192\u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 \u092e\u093e\u0902\u0938\u092a\u0947\u0936\u0940, \u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 \u0918\u0902\u091f\u0940\u2192\u0927\u094d\u0935\u0928\u093f B) \u0915\u0947\u0935\u0932 \u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 C) \u0915\u0947\u0935\u0932 \u0930\u093e\u0938\u093e\u092f\u0928\u093f\u0915 D) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A)<\/b><br><br>\n\n<b>Q6. \u0917\u0924\u093f\u091c \u090a\u0930\u094d\u091c\u093e \u0938\u0942\u0924\u094d\u0930 \u0915\u0948\u0938\u0947 \u0928\u093f\u0915\u0932\u093e? [\u092a\u0947\u091c 121-122 \u0938\u092e\u0940\u0915\u0930\u0923 7.4 7.5 7.6]<\/b><br>\nA) \u0917\u0924\u093f \u0915\u0947 \u0915\u093e\u0930\u0923 \u090a\u0930\u094d\u091c\u093e \u0917\u0924\u093f\u091c - \u0938\u093e\u0907\u0915\u093f\u0932 \u0932\u0941\u0922\u093c\u0915\u0924\u0940 \u0917\u0947\u0902\u0926 - \u0938\u094d\u0925\u093f\u0930 \u0915\u0940 \u0936\u0942\u0928\u094d\u092f - \u092a\u094d\u0930\u093e\u0930\u0902\u092d\u093f\u0915 u \u0905\u0902\u0924\u093f\u092e v \u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928 s \u0928\u093f\u092f\u0924 \u092c\u0932 F \u0924\u094d\u0935\u0930\u0923 a \u0938\u092e\u0940\u0915\u0930\u0923 v\u00b2=u\u00b2+2as \u2192 s=(v\u00b2-u\u00b2)\/2a \u0938\u092e\u0940\u0915\u0930\u0923 7.4 W=F\u00d7s=ma\u00d7s=\u00bdm(v\u00b2-u\u00b2)=\u00bdmv\u00b2-\u00bdmu\u00b2 \u0938\u092e\u0940\u0915\u0930\u0923 7.5 \u0915\u093e\u0930\u094d\u092f-\u090a\u0930\u094d\u091c\u093e \u0938\u0947 \u092a\u0930\u093f\u0935\u0930\u094d\u0924\u0928 - u0 \u0924\u094b \u0905\u0902\u0924\u093f\u092e \u0917\u0924\u093f\u091c K=\u00bdmv\u00b2 \u0938\u092e\u0940\u0915\u0930\u0923 7.6 \u091c\u0942\u0932 \u0926\u093f\u0936\u093e \u0928\u0939\u0940\u0902 \u0927\u0928\u093e\u0924\u094d\u092e\u0915 \u0915\u093e\u0930\u094d\u092f \u0935\u0947\u0917 \u092c\u0922\u093c\u0947 \u0917\u0924\u093f\u091c \u092c\u0922\u093c\u0947 \u090b\u0923\u093e\u0924\u094d\u092e\u0915 \u0918\u091f\u0947 \u0915\u093e\u0930\u094d\u092f \u0936\u0942\u0928\u094d\u092f \u0938\u094d\u0925\u093f\u0930 B) \u0915\u0947\u0935\u0932 mv\u00b2 C) \u0915\u0947\u0935\u0932 \u00bdm D) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A)<\/b><br><br>\n\n<b>Q7. \u0935\u0947\u0917 \u0926\u094b\u0917\u0941\u0928\u093e \u0924\u094b \u0917\u0924\u093f\u091c \u0915\u093f\u0924\u0928\u0940? [\u092a\u0947\u091c 122 \u0909\u0926\u093e\u0939\u0930\u0923 7.4 7.5]<\/b><br>\nA) v \u092a\u0930 K=\u00bdmv\u00b2 2v \u092a\u0930 4 \u0917\u0941\u0928\u093e - \u0917\u0947\u0902\u0926 0.2kg 43m\/s \u092a\u0930 184.9J B) 2 \u0917\u0941\u0928\u093e C) same D) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A) 4 \u0917\u0941\u0928\u093e<\/b><br>\n\n<\/div><\/div>\n\n<div id=\"bh7-2\" style=\"display:none;\"><div style=\"background:#1565c0;color:#fff;padding:6px 14px;border-radius:20px;font-size:13px;font-weight:bold;display:inline-block;margin-bottom:8px;\">\ud83d\udd35 \u092d\u093e\u0917 2\/4 - Q8-Q14<\/div><div style=\"background:#fff;border:1.5px solid #bf360c;border-radius:10px;padding:12px;font-size:14px;line-height:1.9;height:580px;overflow-y:auto;\">\n\n<b>Q8. \u091c\u0947\u091f \u0935\u093f\u092e\u093e\u0928 \u0915\u093e \u0935\u0947\u0917 \u0915\u093f\u0924\u0928\u093e? [\u092a\u0947\u091c 123 \u0909\u0926\u093e\u0939\u0930\u0923 7.6]<\/b><br>\nA) 15000kg \u0935\u093f\u092e\u093e\u0928 \u0921\u0947\u0915 367500N \u092c\u0932 100m \u092e\u0947\u0902 \u0930\u094b\u0915\u0928\u093e - \u0915\u093e\u0930\u094d\u092f =367500\u00d7(-100) \u090b\u0923\u093e\u0924\u094d\u092e\u0915 -\u00bd\u00d715000\u00d7v\u00b2=-367500\u00d7100 \u2192v=70m\/s=252km\/h B) 35m\/s C) 20m\/s D) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A)<\/b><br><br>\n\n<b>Q9. \u0938\u094d\u0925\u093f\u0924\u093f\u091c \u090a\u0930\u094d\u091c\u093e \u0915\u094d\u092f\u093e \u0939\u0948? [\u092a\u0947\u091c 124 \u091a\u093f\u0924\u094d\u0930 7.13-7.16]<\/b><br>\nA) \u0935\u093f\u0930\u0942\u092a\u0923 \u092f\u093e \u0938\u093e\u092a\u0947\u0915\u094d\u0937 \u0938\u094d\u0925\u093f\u0924\u093f \u0915\u0947 \u0915\u093e\u0930\u0923 \u091c\u092e\u093e \u090a\u0930\u094d\u091c\u093e \u0938\u094d\u0925\u093f\u0924\u093f\u091c \u0915\u0939\u0932\u093e\u0924\u0940 \u0939\u0948 - \u0917\u0941\u0932\u0947\u0932 \u0916\u093f\u0902\u091a\u093e \u092c\u0948\u0902\u0921 \u0906\u0917\u0947 \u092b\u0947\u0902\u0915\u0924\u093e, \u0927\u0928\u0941\u0937 \u0924\u0940\u0930, \u0938\u094d\u092a\u094d\u0930\u093f\u0902\u0917 \u0916\u093f\u0902\u091a\u0928\u093e \u0926\u092c\u0928\u093e \u0906\u0915\u093e\u0930 \u092c\u0926\u0932\u0928\u093e \u090a\u0930\u094d\u091c\u093e \u091c\u092e\u093e \u0935\u093f\u0928\u094d\u092f\u093e\u0938 \u0906\u0915\u093e\u0930 \u0915\u0947 \u0915\u093e\u0930\u0923 \u091b\u094b\u0921\u093c\u0928\u0947 \u092a\u0930 \u0935\u093e\u092a\u0938 \u0917\u0924\u093f\u091c \u092e\u0947\u0902, \u091a\u0941\u0902\u092c\u0915 \u0935\u093f\u092a\u0930\u0940\u0924 \u0927\u094d\u0930\u0941\u0935 \u0905\u0932\u0917 \u0915\u0930\u0928\u0947 \u092c\u0932 \u091b\u094b\u0921\u093c\u0928\u0947 \u092a\u0930 \u092a\u093e\u0938 \u0906\u0928\u093e \u0917\u0924\u093f\u091c \u092e\u091f\u0930 \u0915\u0941\u091a\u0932\u0928\u093e, \u0935\u093f\u0926\u094d\u092f\u0941\u0924 \u0906\u0935\u0947\u0936 \u0905\u0932\u0917 \u091c\u092e\u093e, \u0917\u0947\u0902\u0926 \u092a\u0943\u0925\u094d\u0935\u0940 \u0905\u0932\u0917 \u091c\u092e\u093e \u0938\u093e\u092a\u0947\u0915\u094d\u0937 \u0938\u094d\u0925\u093f\u0924\u093f B) \u0915\u0947\u0935\u0932 \u0938\u094d\u092a\u094d\u0930\u093f\u0902\u0917 C) \u0915\u0947\u0935\u0932 \u091a\u0941\u0902\u092c\u0915 D) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A)<\/b><br><br>\n\n<b>Q10. \u0917\u0941\u0930\u0941\u0924\u094d\u0935\u0940\u092f \u0938\u094d\u0925\u093f\u0924\u093f\u091c U=mgh \u0915\u0948\u0938\u0947? [\u092a\u0947\u091c 125 \u0938\u092e\u0940\u0915\u0930\u0923 7.7 7.8 \u0909\u0926\u093e\u0939\u0930\u0923 7.7]<\/b><br>\nA) \u092a\u0943\u0925\u094d\u0935\u0940 \u0917\u0947\u0902\u0926 \u0928\u093f\u0915\u093e\u092f \u092a\u0943\u0925\u094d\u0935\u0940 \u092c\u0939\u0941\u0924 \u092d\u093e\u0930\u0940 \u0917\u0947\u0902\u0926 \u0915\u0940 \u0913\u0930 \u0928\u0939\u0940\u0902 \u0939\u093f\u0932\u0924\u0940 \u0907\u0938\u0932\u093f\u090f \u0917\u0947\u0902\u0926 \u0915\u0940 \u0917\u0941\u0930\u0941\u0924\u094d\u0935\u0940\u092f \u0938\u094d\u0925\u093f\u0924\u093f\u091c - \u0930\u0947\u0924 \u092e\u0947\u0902 1m 2m \u0917\u0921\u094d\u0922\u093e \u0905\u0927\u093f\u0915 \u090a\u0901\u091a\u093e\u0908 \u0917\u0939\u0930\u093e \u0917\u0921\u094d\u0922\u093e \u0905\u0927\u093f\u0915 \u090a\u0901\u091a\u093e\u0908 \u0905\u0927\u093f\u0915 \u0938\u094d\u0925\u093f\u0924\u093f\u091c - \u091c\u092e\u0940\u0928 \u092a\u0930 \u0936\u0942\u0928\u094d\u092f \u092e\u093e\u0928 \u0927\u0940\u0930\u0947 \u090a\u0901\u091a\u093e\u0908 h \u0924\u0915 \u0909\u0920\u093e\u0928\u0947 \u092c\u0932=mg \u0915\u093e\u0930\u094d\u092f W=mg\u00d7h=mgh \u0938\u092e\u0940\u0915\u0930\u0923 7.7 \u0915\u093e\u0930\u094d\u092f-\u090a\u0930\u094d\u091c\u093e \u0938\u0947 \u092a\u0930\u093f\u0935\u0930\u094d\u0924\u0928 U=mgh \u0938\u092e\u0940\u0915\u0930\u0923 7.8 \u091c\u0942\u0932 - \u0917\u0947\u0902\u0926 200g 10m \u092a\u0930 20J B) \u0915\u0947\u0935\u0932 mg C) \u0915\u0947\u0935\u0932 h D) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A)<\/b><br><br>\n\n<b>Q11. \u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 \u090a\u0930\u094d\u091c\u093e \u0938\u0902\u0930\u0915\u094d\u0937\u0923 \u0915\u094d\u092f\u093e? [\u092a\u0947\u091c 126-127 \u0938\u092e\u0940\u0915\u0930\u0923 7.9 7.10]<\/b><br>\nA) \u0917\u0924\u093f\u091c+\u0938\u094d\u0925\u093f\u0924\u093f\u091c=\u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 - \u092c\u093f\u0902\u0926\u0941 A \u090a\u0901\u091a\u093e\u0908 h u0 \u0938\u094d\u0925\u093f\u0924\u093f\u091c mgh \u0938\u092e\u0940\u0915\u0930\u0923 7.9a \u0917\u0924\u093f\u091c0 \u0938\u092e\u0940\u0915\u0930\u0923 7.9b \u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 mgh \u0938\u092e\u0940\u0915\u0930\u0923 7.9c - \u0917\u093f\u0930\u0924\u0947 \u0938\u092e\u092f t \u092c\u093f\u0902\u0926\u0941 B \u0935\u0947\u0917 gt \u090a\u0901\u091a\u093e\u0908 h'=h-\u00bdgt\u00b2 \u0938\u094d\u0925\u093f\u0924\u093f\u091c mgh' \u0938\u092e\u0940\u0915\u0930\u0923 7.10a \u0917\u0924\u093f\u091c \u00bdm(gt)\u00b2 \u0938\u092e\u0940\u0915\u0930\u0923 7.10b \u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 mgh \u0938\u092e\u0940\u0915\u0930\u0923 7.10c \u0928\u093f\u092f\u0924 - \u0938\u094d\u0925\u093f\u0924\u093f\u091c \u0918\u091f\u0924\u0940 \u0917\u0924\u093f\u091c \u092c\u0922\u093c\u0924\u0940 \u0916\u094b\u0908 \u0938\u094d\u0925\u093f\u0924\u093f\u091c \u0917\u0924\u093f\u091c \u092e\u0947\u0902 - \u092c\u093e\u0939\u0930\u0940 \u092c\u0932 \u0928\u0939\u0940\u0902 \u0924\u094b \u0938\u0902\u0930\u0915\u094d\u0937\u093f\u0924 - \u0932\u094b\u0932\u0915 \u091a\u093f\u0924\u094d\u0930 7.20 P \u092a\u0930 \u0938\u094d\u0925\u093f\u0924\u093f\u091c mgh Q \u092a\u0930 \u0917\u0924\u093f\u091c R \u092a\u0930 \u092b\u093f\u0930 \u0938\u094d\u0925\u093f\u0924\u093f\u091c same \u090a\u0901\u091a\u093e\u0908 \u0918\u0930\u094d\u0937\u0923 \u0938\u0947 \u0927\u0940\u0930\u0947 \u0930\u0941\u0915\u0928\u093e B) \u0915\u0947\u0935\u0932 \u0938\u094d\u0925\u093f\u0924\u093f\u091c C) \u0915\u0947\u0935\u0932 \u0917\u0924\u093f\u091c D) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A)<\/b><br><br>\n\n<b>Q12. \u092c\u091a\u094d\u091a\u093e \u0938\u094d\u0932\u093e\u0907\u0921 \u0928\u0940\u091a\u0947 \u0935\u0947\u0917 \u0915\u093f\u0924\u0928\u093e? [\u092a\u0947\u091c 128 \u0909\u0926\u093e\u0939\u0930\u0923 7.8]<\/b><br>\nA) \u090a\u092a\u0930 \u0938\u094d\u0925\u093f\u0924\u093f\u091c mgh \u0928\u0940\u091a\u0947 \u0917\u0924\u093f\u091c \u00bdmv\u00b2 \u092a\u0942\u0930\u0940 \u0917\u0924\u093f\u091c \u092e\u0947\u0902 \u092c\u0926\u0932\u0940 \u0918\u0930\u094d\u0937\u0923 \u0928\u0917\u0923\u094d\u092f \u00bdmv\u00b2=mgh \u2192v=\u221a(2gh) \u0915\u0947\u0935\u0932 \u090a\u0901\u091a\u093e\u0908 \u092a\u0930 \u0928\u093f\u0930\u094d\u092d\u0930 \u0906\u0915\u093e\u0930 \u0935\u091c\u0928 matter \u0928\u0939\u0940\u0902 - \u0905\u0932\u0917 \u0935\u091c\u0928 same \u0938\u094d\u0932\u093e\u0907\u0921 same \u0935\u0947\u0917 B) \u0935\u091c\u0928 \u092a\u0930 \u0928\u093f\u0930\u094d\u092d\u0930 C) \u0906\u0915\u093e\u0930 \u092a\u0930 \u0928\u093f\u0930\u094d\u092d\u0930 D) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A) v=\u221a(2gh)<\/b><br><br>\n\n<b>Q13. \u090f\u0938\u094d\u0915\u0947\u092a \u0930\u0948\u0902\u092a \u0932\u0902\u092c\u093e\u0908 20m \u0915\u0948\u0938\u0947 \u0928\u093f\u0915\u0932\u0940? [\u092a\u0947\u091c 128-129 \u0909\u0926\u093e\u0939\u0930\u0923 7.9]<\/b><br>\nA) \u091f\u094d\u0930\u0915 10000kg 72km\/h 20m\/s \u092c\u094d\u0930\u0947\u0915 \u092b\u0947\u0932 30\u00b0 \u0930\u0947\u0924 \u092c\u0932 50000N \u0935\u093f\u092a\u0930\u0940\u0924 - \u092a\u094d\u0930\u093e\u0930\u0902\u092d\u093f\u0915 \u0917\u0924\u093f\u091c \u00bd\u00d710000\u00d720\u00b2=2000000J \u092a\u094d\u0930\u093e\u0930\u0902\u092d\u093f\u0915 \u0938\u094d\u0925\u093f\u0924\u093f\u091c0 \u0915\u0941\u0932 2000000J \u0926\u0942\u0930\u0940 d \u090a\u0901\u091a\u093e\u0908 d\/2 \u0938\u0902\u0915\u0947\u0924 30\u00b0 \u092a\u0930 2 \u092a\u0930 1 \u0932\u0902\u092c\u0935\u0924 \u0905\u0902\u0924\u093f\u092e \u0917\u0924\u093f\u091c0 \u0905\u0902\u0924\u093f\u092e \u0938\u094d\u0925\u093f\u0924\u093f\u091c mg\u00d7d\/2=50000\u00d7d \u0915\u0941\u0932 \u0905\u0902\u0924\u093f\u092e 50000d \u092a\u0930\u093f\u0935\u0930\u094d\u0924\u0928 50000d-2000000 \u0930\u0947\u0924 \u0915\u093e\u0930\u094d\u092f -50000d \u0915\u093e\u0930\u094d\u092f-\u090a\u0930\u094d\u091c\u093e \u0915\u093e\u0930\u094d\u092f=\u092a\u0930\u093f\u0935\u0930\u094d\u0924\u0928 \u2192-50000d=50000d-2000000 \u2192100000d=2000000 \u2192d=20m \u0928\u094d\u092f\u0942\u0928\u0924\u092e \u0932\u0902\u092c\u093e\u0908 - \u0928\u094d\u092f\u0942\u091f\u0928 \u0928\u093f\u092f\u092e \u0915\u0920\u093f\u0928 \u0938\u0902\u0930\u0915\u094d\u0937\u0923 \u0906\u0938\u093e\u0928 B) 10m C) 40m D) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A) 20m<\/b><br><br>\n\n<b>Q14. \u0936\u0915\u094d\u0924\u093f \u0915\u094d\u092f\u093e \u0939\u0948? [\u092a\u0947\u091c 129 \u0938\u092e\u0940\u0915\u0930\u0923 7.11 \u0909\u0926\u093e\u0939\u0930\u0923 7.10 7.11]<\/b><br>\nA) \u0915\u093e\u0930\u094d\u092f \u0915\u0930\u0928\u0947 \u0915\u0940 \u0926\u0930 \u0936\u0915\u094d\u0924\u093f - \u0914\u0938\u0924 \u0936\u0915\u094d\u0924\u093f P=\u0915\u093e\u0930\u094d\u092f\/\u0938\u092e\u092f W\/t \u0938\u092e\u0940\u0915\u0930\u0923 7.11 \u0905\u0927\u093f\u0915 \u0915\u093e\u0930\u094d\u092f same \u0938\u092e\u092f \u0905\u0927\u093f\u0915 \u0936\u0915\u094d\u0924\u093f same \u0915\u093e\u0930\u094d\u092f \u0915\u092e \u0938\u092e\u092f \u0905\u0927\u093f\u0915 \u0936\u0915\u094d\u0924\u093f SI \u0935\u093e\u091f W 1W=1J \u092a\u094d\u0930\u0924\u093f \u0938\u0947\u0915\u0902\u0921 1W=1J s\u207b\u00b9 - \u092d\u093e\u0930\u094b\u0924\u094d\u0924\u094b\u0932\u0915 75kg 2m 5s \u0915\u093e\u0930\u094d\u092f mgh1500J \u0936\u0915\u094d\u0924\u093f 1500\/5=300W - \u0915\u093e\u0930 1000kg 20m\/s 10s \u0915\u093e\u0930\u094d\u092f 200000J \u0936\u0915\u094d\u0924\u093f 20000W - \u0905\u0936\u094d\u0935 \u0936\u0915\u094d\u0924\u093f hp 1hp=746W - \u0935\u093e\u091f \u091c\u0947\u092e\u094d\u0938 \u0935\u093e\u091f \u092d\u093e\u092a \u0907\u0902\u091c\u0928 \u0918\u0942\u0930\u094d\u0923\u0928 \u0917\u0924\u093f \u092a\u0939\u093f\u090f B) \u0915\u0947\u0935\u0932 \u0915\u093e\u0930\u094d\u092f C) \u0915\u0947\u0935\u0932 \u0938\u092e\u092f D) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A)<\/b><br>\n\n<\/div><\/div>\n\n<div id=\"bh7-3\" style=\"display:none;\"><div style=\"background:#2e7d32;color:#fff;padding:6px 14px;border-radius:20px;font-size:13px;font-weight:bold;display:inline-block;margin-bottom:8px;\">\ud83d\udfe2 \u092d\u093e\u0917 3\/4 - Q15-Q20<\/div><div style=\"background:#fff;border:1.5px solid #bf360c;border-radius:10px;padding:12px;font-size:14px;line-height:1.9;height:580px;overflow-y:auto;\">\n\n<b>Q15. \u0938\u0930\u0932 \u092e\u0936\u0940\u0928\u0947\u0902 \u0914\u0930 \u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 \u0932\u093e\u092d \u0915\u094d\u092f\u093e? [\u092a\u0947\u091c 130 \u0938\u092e\u0940\u0915\u0930\u0923 7.12]<\/b><br>\nA) \u0917\u0941\u0930\u0941\u0924\u094d\u0935 \u0905\u0928\u094d\u092f \u092c\u0932\u094b\u0902 \u0915\u0947 \u0935\u093f\u0930\u0941\u0926\u094d\u0927 \u092d\u093e\u0930\u0940 \u0935\u0938\u094d\u0924\u0941 \u0909\u0920\u093e\u0928\u093e \u091a\u0932\u093e\u0928\u093e \u0915\u0941\u0932 \u0915\u093e\u0930\u094d\u092f \u0915\u092e \u0928\u0939\u0940\u0902 \u0915\u093f\u092f\u093e \u091c\u093e \u0938\u0915\u0924\u093e \u0932\u0947\u0915\u093f\u0928 \u092c\u0932 \u092a\u0930\u093f\u092e\u093e\u0923 \u0926\u093f\u0936\u093e \u092c\u0926\u0932\u0915\u0930 \u0906\u0938\u093e\u0928 \u0915\u0930\u0928\u0947 \u0935\u093e\u0932\u0940 \u092f\u0941\u0915\u094d\u0924\u093f \u0938\u0930\u0932 \u092e\u0936\u0940\u0928\u0947\u0902 - \u0924\u0940\u0928 \u092e\u0936\u0940\u0928\u0947\u0902 \u0918\u093f\u0930\u0928\u0940 \u0906\u0928\u0924 \u0924\u0932 \u0909\u0924\u094d\u0924\u094b\u0932\u0915 \u0939\u092e \u091c\u094b \u092c\u0932 \u0932\u0917\u093e\u0924\u0947 \u092a\u094d\u0930\u092f\u093e\u0938 \u0939\u0930\u093e\u0928\u093e \u092d\u093e\u0930 - \u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 \u0932\u093e\u092d=\u092d\u093e\u0930\/\u092a\u094d\u0930\u092f\u093e\u0938 \u0938\u092e\u0940\u0915\u0930\u0923 7.12 B) \u0915\u0947\u0935\u0932 \u092a\u094d\u0930\u092f\u093e\u0938 C) \u0915\u0947\u0935\u0932 \u092d\u093e\u0930 D) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A)<\/b><br><br>\n\n<b>Q16. \u0918\u093f\u0930\u0928\u0940 \u0915\u094d\u092f\u093e? \u0938\u094d\u0925\u093f\u0930 \u0914\u0930 \u091a\u0932 \u0918\u093f\u0930\u0928\u0940 \u0915\u093e \u0932\u093e\u092d? [\u092a\u0947\u091c 130 \u091a\u093f\u0924\u094d\u0930 7.23-7.25]<\/b><br>\nA) \u092a\u0939\u093f\u092f\u093e \u0916\u093e\u0901\u091a\u093e \u0930\u0938\u094d\u0938\u0940 \u0928\u093f\u0930\u094d\u0926\u0947\u0936 \u091a\u093f\u0924\u094d\u0930 7.23 \u0938\u094d\u0925\u093f\u0930 \u0918\u093f\u0930\u0928\u0940 \u092c\u0932 \u092a\u0930\u093f\u092e\u093e\u0923 \u0915\u092e \u0928\u0939\u0940\u0902 \u0915\u0947\u0935\u0932 \u0926\u093f\u0936\u093e \u092c\u0926\u0932\u0924\u0940 \u0928\u0940\u091a\u0947 \u0916\u0940\u0902\u091a\u0928\u093e \u0906\u0938\u093e\u0928 \u0938\u0940\u0927\u0947 \u090a\u092a\u0930 \u0909\u0920\u093e\u0928\u0947 \u0938\u0947 \u091a\u093f\u0924\u094d\u0930 7.24a \u0938\u0940\u0927\u0947 7.24b \u0918\u093f\u0930\u0928\u0940 \u0938\u0941\u0935\u093f\u0927\u093e \u0926\u093f\u0936\u093e \u092a\u094d\u0930\u092f\u093e\u0938 \u092c\u0930\u093e\u092c\u0930 \u092a\u0930\u093f\u092e\u093e\u0923 \u0932\u093e\u092d 1 \u0938\u092e\u0940\u0915\u0930\u0923 7.12 - \u091a\u0932 \u0918\u093f\u0930\u0928\u0940 \u092a\u094d\u0930\u0923\u093e\u0932\u0940 \u091a\u093f\u0924\u094d\u0930 7.25 \u0932\u093e\u092d 1 \u0938\u0947 \u0905\u0927\u093f\u0915 \u092d\u093e\u0930\u0940 \u0915\u092e \u092a\u094d\u0930\u092f\u093e\u0938 \u092e\u0947\u0902 \u0909\u0920\u093e\u0928\u093e \u092d\u093e\u0930 \u091a\u0932 \u0918\u093f\u0930\u0928\u0940 \u0938\u0947 \u091c\u0941\u0921\u093c\u093e \u0930\u0938\u094d\u0938\u0940 \u090f\u0915 \u0938\u093f\u0930\u093e \u0938\u094d\u0925\u093f\u0930 \u0926\u0942\u0938\u0930\u093e \u092e\u0941\u0915\u094d\u0924 \u092a\u094d\u0930\u092f\u093e\u0938 \u0932\u093f\u092b\u094d\u091f \u0915\u094d\u0930\u0947\u0928 \u092e\u0947\u0902 \u0935\u094d\u092f\u093e\u092a\u0915 B) \u0915\u0947\u0935\u0932 \u0938\u094d\u0925\u093f\u0930 \u0932\u093e\u092d0 C) \u0915\u0947\u0935\u0932 \u091a\u0932 \u0932\u093e\u092d1 D) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A)<\/b><br><br>\n\n<b>Q17. \u0906\u0928\u0924 \u0924\u0932 \u0915\u093e \u0932\u093e\u092d L\/h \u0915\u0948\u0938\u0947? [\u092a\u0947\u091c 131-132 \u0938\u092e\u0940\u0915\u0930\u0923 7.13 \u091a\u093f\u0924\u094d\u0930 7.26-7.29 \u0909\u0926\u093e\u0939\u0930\u0923 7.12]<\/b><br>\nA) \u092d\u093e\u0930\u0940 \u092c\u0915\u094d\u0938\u093e \u092a\u094d\u0932\u0947\u091f\u092b\u0949\u0930\u094d\u092e \u092a\u0930 \u0932\u0902\u092c\u0935\u0924 \u0909\u0920\u093e\u0928\u093e Fig7.26a \u0935\u091c\u0928 \u092c\u0930\u093e\u092c\u0930 \u092c\u0932 \u092d\u093e\u0930\u0940 \u0939\u094b \u0924\u094b \u091a\u093f\u0915\u0928\u0940 \u0924\u0916\u094d\u0924\u0940 \u0906\u0928\u0924 \u0930\u0916 Fig7.26b \u0927\u0915\u0947\u0932\u0928\u093e \u091b\u094b\u091f\u093e \u092c\u0932 \u0917\u0924\u093f\u0935\u093f\u0927\u093f7.3 \u0924\u0916\u094d\u0924\u0940 1.5m \u0916\u093f\u0932\u094c\u0928\u093e \u0917\u093e\u0921\u093c\u0940 \u0938\u094d\u092a\u094d\u0930\u093f\u0902\u0917 \u0924\u0941\u0932\u093e \u090a\u0901\u091a\u093e\u0908 0.5m \u0915\u093f\u0924\u093e\u092c \u0922\u0947\u0930 \u0932\u0902\u092c\u0935\u0924 \u0909\u0920\u093e\u0928\u0947 \u0935\u091c\u0928 \u092a\u0922\u093c\u0928\u093e \u0924\u0916\u094d\u0924\u0940 \u0930\u0916 \u0916\u0940\u0902\u091a\u0928\u093e \u092a\u0922\u093c\u0928\u093e \u091b\u094b\u091f\u093e \u0915\u092e \u0922\u093e\u0932 Fig7.27b \u0914\u0930 \u091b\u094b\u091f\u093e \u092c\u0932 \u0932\u0947\u0915\u093f\u0928 \u092c\u0921\u093c\u0940 \u0926\u0942\u0930\u0940 same \u090a\u0901\u091a\u093e\u0908 - \u0935\u091c\u0928 mg \u092a\u094d\u0930\u092f\u093e\u0938 F' \u090a\u0901\u091a\u093e\u0908 h \u0932\u0902\u092c\u093e\u0908 L \u0928\u093f\u092f\u0924 \u0917\u0924\u093f \u0915\u093e\u0930\u094d\u092f F'\u00d7L \u0938\u094d\u0925\u093f\u0924\u093f\u091c \u092c\u0922\u093c\u0924 mgh \u0915\u093e\u0930\u094d\u092f-\u090a\u0930\u094d\u091c\u093e \u0918\u0930\u094d\u0937\u0923 \u0928\u0917\u0923\u094d\u092f F'\u00d7L=mgh \u2192mg\/F'=L\/h \u0905\u092c mg \u092d\u093e\u0930 F' \u092a\u094d\u0930\u092f\u093e\u0938 \u0932\u093e\u092d=\u092d\u093e\u0930\/\u092a\u094d\u0930\u092f\u093e\u0938=mg\/F'=L\/h \u0938\u092e\u0940\u0915\u0930\u09237.13 L \u092c\u0921\u093c\u093e h \u0938\u0947 \u092c\u0932 F' mg \u0938\u0947 \u0915\u092e \u0932\u093e\u092d 1 \u0938\u0947 \u0905\u0927\u093f\u0915 L \u092c\u0922\u093c\u093e \u0915\u092e \u0922\u093e\u0932 \u092a\u094d\u0930\u092f\u093e\u0938 \u0914\u0930 \u0915\u092e - \u0935\u094d\u092f\u0915\u094d\u0924\u093f \u0930\u0948\u0902\u092a \u0938\u0940\u0922\u093c\u0940 30cm \u090a\u0901\u091a\u0940 \u091a\u094c\u0921\u093c\u093e\u0908 40cm \u0932\u0902\u092c\u093e\u0908 AC50cm \u0938\u092e\u0915\u094b\u0923 3-4-5 \u0932\u093e\u092d L\/h=50\/30=1.67 - \u0915\u093e\u0930\u094d\u092f \u092c\u0932\u00d7\u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928 same \u092c\u0932 \u0918\u091f\u093e \u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928 \u092c\u0922\u093c\u093e \u0915\u093e\u0930\u094d\u092f \u0928\u093f\u092f\u0924 \u0928\u094b\u091f \u092a\u0947\u091c132 B) \u0915\u0947\u0935\u0932 L C) \u0915\u0947\u0935\u0932 h D) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A) L\/h<\/b><br><br>\n\n<b>Q18. \u0909\u0924\u094d\u0924\u094b\u0932\u0915 \u0915\u094d\u092f\u093e? F1d1=F2d2 \u0915\u0948\u0938\u0947? [\u092a\u0947\u091c 133 \u0938\u092e\u0940\u0915\u0930\u0923 7.14 \u091a\u093f\u0924\u094d\u0930 7.31 7.32]<\/b><br>\nA) \u0917\u0924\u093f\u0935\u093f\u0927\u093f7.4 \u0938\u094d\u0915\u0947\u0932 \u092a\u0947\u0902\u0938\u093f\u0932 \u0930\u092c\u0921\u093c \u0938\u094d\u091f\u0947\u092a\u0932\u0930 \u0938\u094d\u0915\u0947\u0932 \u092a\u0947\u0902\u0938\u093f\u0932 \u092a\u0930 \u090f\u0915 \u0938\u093f\u0930\u0947 \u092a\u093e\u0938 \u0938\u094d\u091f\u0947\u092a\u0932\u0930 \u0926\u0942\u0938\u0930\u0947 \u0938\u093f\u0930\u0947 \u0930\u092c\u0921\u093c \u092d\u093e\u0930\u0940 \u0938\u094d\u091f\u0947\u092a\u0932\u0930 \u0939\u0932\u094d\u0915\u0940 \u0930\u092c\u0921\u093c \u0938\u0947 \u0909\u0920\u093e \u0938\u094d\u0915\u0947\u0932 \u0938\u0930\u0932 \u092e\u0936\u0940\u0928 \u0909\u0924\u094d\u0924\u094b\u0932\u0915 \u0915\u0920\u094b\u0930 \u091b\u0921\u093c \u0918\u0942\u092e\u0924\u0940 \u0938\u094d\u0925\u093f\u0930 \u092c\u093f\u0902\u0926\u0941 \u0938\u0902\u092a\u0930\u094d\u0915 - \u0909\u0924\u094d\u0924\u094b\u0932\u0915 \u0924\u0940\u0928 \u092d\u093e\u0917 \u0906\u0932\u0902\u092c \u0938\u094d\u0925\u093f\u0930 \u092c\u093f\u0902\u0926\u0941 \u0918\u0942\u092e\u0928\u093e \u092d\u093e\u0930 \u0939\u0930\u093e\u0928\u0947 \u0935\u093e\u0932\u093e \u092c\u0932 \u092a\u094d\u0930\u092f\u093e\u0938 \u0932\u0917\u093e\u092f\u093e \u092c\u0932 \u0926\u0942\u0930\u0940 \u092d\u093e\u0930 \u0906\u0932\u0902\u092c \u092d\u093e\u0930 \u092d\u0941\u091c\u093e \u092a\u094d\u0930\u092f\u093e\u0938 \u0906\u0932\u0902\u092c \u092a\u094d\u0930\u092f\u093e\u0938 \u092d\u0941\u091c\u093e - \u091b\u094b\u091f\u093e \u092c\u0932 F1 \u092c\u0921\u093c\u0940 \u0926\u0942\u0930\u0940 d1 \u0926\u0942\u0938\u0930\u0940 \u0913\u0930 \u092c\u0921\u093c\u093e \u092c\u0932 F2 \u092d\u093e\u0930\u0940 \u0935\u0938\u094d\u0924\u0941 \u091b\u094b\u091f\u0940 \u0926\u0942\u0930\u0940 d2 \u0915\u093e\u0930\u094d\u092f \u090f\u0915 \u0938\u093f\u0930\u0947 \u0938\u0947 \u0926\u0942\u0938\u0930\u0947 \u0938\u093f\u0930\u0947 \u0938\u094d\u0925\u093e\u0928\u093e\u0902\u0924\u0930\u093f\u0924 Eq7.1 F1\u00d7d1=F2\u00d7d2 \u0938\u092e\u0940\u0915\u0930\u09237.14 \u092a\u094d\u0930\u092f\u093e\u0938 \u092d\u0941\u091c\u093e \u092c\u0922\u093c\u093e \u092c\u0921\u093c\u093e \u092c\u0932 F2 \u092d\u093e\u0930 \u092a\u094d\u0930\u092f\u093e\u0938 F1 \u0924\u0941\u0932\u0928\u093e - \u0909\u0924\u094d\u0924\u094b\u0932\u0915 \u092c\u0932 \u0915\u092e \u0915\u0930\u0924\u093e \u0915\u0941\u0932 \u0915\u093e\u0930\u094d\u092f \u0928\u0939\u0940\u0902 B) \u0915\u0947\u0935\u0932 F1 C) \u0915\u0947\u0935\u0932 F2 D) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A)<\/b><br><br>\n\n<b>Q19. \u0924\u0930\u093e\u091c\u0942 \u0938\u0902\u0924\u0941\u0932\u0928 \u0914\u0930 \u0932\u093e\u092d \u092a\u094d\u0930\u092f\u093e\u0938 \u092d\u0941\u091c\u093e\/\u092d\u093e\u0930 \u092d\u0941\u091c\u093e \u0915\u0948\u0938\u0947? [\u092a\u0947\u091c 134 \u0938\u092e\u0940\u0915\u0930\u0923 7.15 7.16 \u0909\u0926\u093e\u0939\u0930\u0923 7.13]<\/b><br>\nA) \u0917\u0924\u093f\u0935\u093f\u0927\u093f7.5 \u0924\u0930\u093e\u091c\u0942 \u0938\u094d\u0915\u0947\u0932 \u0927\u093e\u0917\u093e \u0915\u093e\u0917\u091c \u0915\u092a \u0938\u093f\u0915\u094d\u0915\u0947 \u0935\u091c\u0928 \u0927\u093e\u0917\u093e \u092c\u0940\u091a \u092e\u0947\u0902 \u0906\u0932\u0902\u092c \u0932\u091f\u0915\u093e \u092c\u0940\u092e \u091a\u093f\u0924\u094d\u09307.33 \u0926\u094b\u0928\u094b\u0902 \u0913\u0930 \u0915\u092a \u0938\u092e\u0924\u0932 \u0938\u0902\u0924\u0941\u0932\u0928 1 \u0938\u093f\u0915\u094d\u0915\u093e \u092c\u093e\u090f\u0901 \u092a\u094d\u0930\u092f\u093e\u0938 1 \u0926\u093e\u090f\u0901 \u092d\u093e\u0930 \u0915\u094d\u0937\u0948\u0924\u093f\u091c 2 \u0938\u093f\u0915\u094d\u0915\u0947 \u0926\u093e\u090f\u0901 \u091d\u0941\u0915\u093e\u0935 \u092d\u093e\u0930\u0940 \u092a\u0932\u0921\u093c\u093e \u0915\u0947\u0902\u0926\u094d\u0930 \u0915\u0947 \u092a\u093e\u0938 \u0932\u0947 \u091c\u093e\u0915\u0930 \u0938\u0902\u0924\u0941\u0932\u0928 \u0926\u0942\u0930\u0940 \u092e\u093e\u092a 4 \u0938\u093f\u0915\u094d\u0915\u0947 8 \u0938\u093f\u0915\u094d\u0915\u0947 \u0924\u093e\u0932\u093f\u0915\u093e7.1 \u0935\u093f\u0936\u094d\u0932\u0947\u0937\u0923 \u0938\u0902\u0924\u0941\u0932\u0928 n1\u00d7L1=n2\u00d7L2 \u092f\u093e \u092a\u094d\u0930\u092f\u093e\u0938\u00d7\u092a\u094d\u0930\u092f\u093e\u0938 \u092d\u0941\u091c\u093e=\u092d\u093e\u0930\u00d7\u092d\u093e\u0930 \u092d\u0941\u091c\u093e \u0938\u092e\u0940\u0915\u0930\u09237.15 \u092a\u094d\u0930\u092f\u093e\u0938 \u092d\u0941\u091c\u093e \u092c\u0922\u093c\u093e \u092a\u094d\u0930\u092f\u093e\u0938 same \u092d\u093e\u0930 \u0915\u092e \u0932\u093e\u092d=\u092d\u093e\u0930\/\u092a\u094d\u0930\u092f\u093e\u0938=\u092a\u094d\u0930\u092f\u093e\u0938 \u092d\u0941\u091c\u093e\/\u092d\u093e\u0930 \u092d\u0941\u091c\u093e \u0938\u092e\u0940\u0915\u0930\u09237.16 \u092a\u094d\u0930\u092f\u093e\u0938 \u092d\u0941\u091c\u093e \u092c\u0922\u093c\u093e \u092c\u0921\u093c\u093e \u092c\u0932 F2 \u092d\u093e\u0930 \u0938\u0947 \u0905\u0927\u093f\u0915 \u0932\u093e\u092d \u0926\u0942\u0930\u0940 \u0905\u0928\u0941\u092a\u093e\u0924 L1\/L2 \u092a\u094d\u0930\u092f\u093e\u0938 \u091b\u094b\u091f\u093e \u0932\u0947\u0915\u093f\u0928 \u092c\u0921\u093c\u0940 \u0926\u0942\u0930\u0940 \u091a\u0932\u0928\u093e \u0915\u0941\u0932 \u0915\u093e\u0930\u094d\u092f same - \u091d\u0942\u0932\u093e \u091a\u093e\u0930 \u0938\u0940\u091f\u0947\u0902 A,B,D,E \u0906\u0932\u0902\u092c C AC=EC=2m BC=DC=1m \u092c\u091a\u094d\u091a\u0947 15kg 30kg \u0938\u0902\u0924\u0941\u0932\u0928 15\u00d72=30\u00d7L L=1m \u0926\u0942\u0938\u0930\u093e \u092c\u091a\u094d\u091a\u093e \u0938\u0940\u091f D B) \u0915\u0947\u0935\u0932 n1L1 C) \u0915\u0947\u0935\u0932 \u0932\u093e\u092d D) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A)<\/b><br><br>\n\n<b>Q20. \u0909\u0924\u094d\u0924\u094b\u0932\u0915 \u0915\u0947 \u0935\u0930\u094d\u0917 \u0915\u094c\u0928 \u0938\u0947? [\u092a\u0947\u091c 135 \u0924\u093e\u0932\u093f\u0915\u093e 7.2 \u091a\u093f\u0924\u094d\u0930 7.35]<\/b><br>\nA) \u0935\u0930\u094d\u0917 I \u0906\u0932\u0902\u092c \u092c\u0940\u091a \u092e\u0947\u0902 \u092d\u093e\u0930 \u092a\u094d\u0930\u092f\u093e\u0938 - \u091a\u093f\u092e\u091f\u093e \u0915\u0948\u0902\u091a\u0940 \u0938\u092c\u094d\u092c\u0932 \u092a\u094d\u0932\u093e\u0938 \u0924\u0930\u093e\u091c\u0942 \u091d\u0942\u0932\u093e, \u0935\u0930\u094d\u0917 II \u092d\u093e\u0930 \u092c\u0940\u091a \u092e\u0947\u0902 \u0906\u0932\u0902\u092c \u092a\u094d\u0930\u092f\u093e\u0938 - \u0928\u0940\u0902\u092c\u0942 \u0928\u093f\u091a\u094b\u0921\u093c \u0920\u0947\u0932\u093e \u092c\u094b\u0924\u0932 \u0916\u094b\u0932\u0928\u0947 \u0935\u093e\u0932\u093e, \u0935\u0930\u094d\u0917 III \u092a\u094d\u0930\u092f\u093e\u0938 \u092c\u0940\u091a \u092e\u0947\u0902 \u0906\u0932\u0902\u092c \u092d\u093e\u0930 - \u091a\u093f\u092e\u091f\u0940 \u091a\u093f\u092e\u091f\u093e \u091d\u093e\u0921\u093c\u0942 \u0939\u0925\u094c\u0921\u093c\u093e \u092a\u0924\u0935\u093e\u0930 - \u0938\u092d\u0940 \u092e\u093e\u092e\u0932\u094b\u0902 \u092e\u0947\u0902 \u092f\u093e\u0902\u0924\u094d\u0930\u093f\u0915 \u090a\u0930\u094d\u091c\u093e \u0938\u0902\u0930\u0915\u094d\u0937\u0923 \u0939\u092e \u091c\u094b \u0915\u093e\u0930\u094d\u092f \u0932\u0917\u093e\u0924\u0947 \u092c\u0930\u093e\u092c\u0930 \u0909\u092a\u092f\u094b\u0917\u0940 \u0915\u093e\u0930\u094d\u092f \u092d\u093e\u0930 \u0918\u0930\u094d\u0937\u0923 \u0928\u0917\u0923\u094d\u092f \u092e\u0936\u0940\u0928\u0947\u0902 \u090a\u0930\u094d\u091c\u093e \u0928\u0939\u0940\u0902 \u092c\u0928\u093e\u0924\u0940 \u0915\u0947\u0935\u0932 \u092a\u094d\u0930\u092d\u093e\u0935\u0940 \u0909\u092a\u092f\u094b\u0917 - \u0922\u0915\u094d\u0915\u0928 \u091a\u092e\u094d\u092e\u091a \u0938\u0947 \u0906\u0938\u093e\u0928 \u091a\u092e\u094d\u092e\u091a \u0909\u0924\u094d\u0924\u094b\u0932\u0915 \u0906\u0932\u0902\u092c \u0915\u093f\u0928\u093e\u0930\u093e \u092a\u094d\u0930\u092f\u093e\u0938 \u092d\u0941\u091c\u093e \u092c\u0921\u093c\u0940 \u092d\u093e\u0930 \u092d\u0941\u091c\u093e \u091b\u094b\u091f\u0940 \u092c\u0932 \u092c\u0922\u093c\u093e \u091a\u093f\u0924\u094d\u09307.35 \u0915\u0948\u0902\u091a\u0940 \u092e\u0947\u0902 \u0915\u0920\u093f\u0928 \u0935\u0938\u094d\u0924\u0941 \u0906\u0932\u0902\u092c \u092a\u093e\u0938 \u0927\u0915\u0947\u0932\u0928\u093e \u092d\u093e\u0930 \u092d\u0941\u091c\u093e \u091b\u094b\u091f\u0940 \u0932\u093e\u092d \u091c\u094d\u092f\u093e\u0926\u093e \u092c\u0932 \u0938\u0924\u0924 \u092e\u0936\u0940\u0928\u0947\u0902 \u092a\u0939\u093f\u090f \u0935\u091c\u0928 \u091a\u0941\u0902\u092c\u0915 \u092a\u094d\u0930\u0938\u094d\u0924\u093e\u0935\u093f\u0924 \u0915\u094b\u0908 \u0915\u093e\u092e \u0928\u0939\u0940\u0902 \u0905\u0938\u0932\u0940 \u092e\u0936\u0940\u0928\u0947\u0902 \u0918\u0930\u094d\u0937\u0923 \u0939\u0935\u093e \u092a\u094d\u0930\u0924\u093f\u0930\u094b\u0927 \u090a\u0937\u094d\u092e\u093e \u0927\u094d\u0935\u0928\u093f \u0939\u093e\u0928\u093f \u0927\u0940\u0930\u0947 \u0930\u0941\u0915\u0924\u0940 B) \u0915\u0947\u0935\u0932 \u0935\u0930\u094d\u0917 I C) \u0915\u0947\u0935\u0932 \u0935\u0930\u094d\u0917 II D) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A)<\/b><br>\n\n<\/div><\/div>\n\n<div id=\"bh7-4\" style=\"display:none;\"><div style=\"background:#004d40;color:#fff;padding:6px 14px;border-radius:20px;font-size:13px;font-weight:bold;display:inline-block;margin-bottom:8px;\">\u2705 \u092d\u093e\u0917 4\/4 - Q21-Q25<\/div><div style=\"background:#fff;border:1.5px solid #bf360c;border-radius:10px;padding:12px;font-size:14px;line-height:1.9;height:580px;overflow-y:auto;\">\n\n<b>Q21. \u0938\u0921\u093c\u0915\u0947\u0902 \u0918\u0941\u092e\u093e\u0935\u0926\u093e\u0930 \u0915\u094d\u092f\u094b\u0902 \u0914\u0930 \u0906\u0928\u0924 \u0938\u0940\u0922\u093c\u0940 \u0906\u0938\u093e\u0928 \u0915\u094d\u092f\u094b\u0902? [\u092a\u0947\u091c 132 \u092a\u094d\u0930\u0936\u094d\u0928 9 10]<\/b><br>\nA) \u092a\u0939\u093e\u0921\u093c\u094b\u0902 \u092a\u0930 \u0938\u0921\u093c\u0915\u0947\u0902 \u0938\u0940\u0927\u0940 \u090a\u092a\u0930 \u0928\u0939\u0940\u0902 \u0918\u0941\u092e\u093e\u0935\u0926\u093e\u0930 \u0939\u0932\u094d\u0915\u0940 \u0922\u093e\u0932 \u0915\u094d\u092f\u094b\u0902 \u091a\u093f\u0924\u094d\u09304.26 \u0915\u094d\u092f\u094b\u0902\u0915\u093f \u0939\u0932\u094d\u0915\u0940 \u0922\u093e\u0932 L \u092c\u0922\u093c\u093e \u092a\u094d\u0930\u092f\u093e\u0938 \u0915\u092e \u0932\u093e\u092d L\/h \u092c\u0922\u093c\u093e - \u090a\u0901\u091a\u0940 \u092e\u0902\u091c\u093f\u0932 \u0906\u0928\u0924 \u0938\u0940\u0922\u093c\u0940 \u0938\u0940\u0927\u0940 \u0938\u0940\u0922\u093c\u0940 \u0938\u0947 \u0906\u0938\u093e\u0928 \u0915\u094d\u092f\u094b\u0902 \u091a\u093f\u0924\u094d\u09307.30 same \u0915\u093e\u0930\u0923 \u0906\u0928\u0924 \u0924\u0932 \u0932\u093e\u092d1 \u0938\u0947 \u0905\u0927\u093f\u0915 \u092c\u0932 \u0915\u092e - \u0915\u093e\u0930\u094d\u092f same \u092c\u0932 \u0918\u091f\u093e \u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928 \u092c\u0922\u093c\u093e \u0928\u093f\u092f\u0924 B) \u0915\u0947\u0935\u0932 \u0938\u0921\u093c\u0915 C) \u0915\u0947\u0935\u0932 \u0938\u0940\u0922\u093c\u0940 D) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A)<\/b><br><br>\n\n<b>Q22. \u0938\u0924\u094d\u092f \u0905\u0938\u0924\u094d\u092f \u0914\u0930 \u0916\u093e\u0932\u0940 \u091c\u0917\u0939 \u092d\u0930\u094b [\u092a\u0947\u091c 136 \u092a\u094d\u0930\u0936\u094d\u09281 \u0938\u093e\u0930\u093e\u0902\u0936 \u092a\u0947\u091c137 \u092a\u094d\u0930\u0936\u094d\u09282]<\/b><br>\nA) \u0938\u0924\u094d\u092f \u0905\u0938\u0924\u094d\u092f (i)\u092c\u0932 \u0932\u0917\u093e\u092f\u093e \u0935\u0938\u094d\u0924\u0941 \u0928\u0939\u0940\u0902 \u0939\u091f\u0940 \u092b\u093f\u0930 \u092d\u0940 \u0915\u093e\u0930\u094d\u092f \u0905\u0938\u0924\u094d\u092f s0 W0 (ii)\u092c\u093e\u0932\u094d\u091f\u0940 \u0932\u0902\u092c\u0935\u0924 \u090a\u092a\u0930 \u0927\u0928\u093e\u0924\u094d\u092e\u0915 \u0915\u093e\u0930\u094d\u092f \u0938\u0924\u094d\u092f same \u0926\u093f\u0936\u093e \u0927\u0928\u093e\u0924\u094d\u092e\u0915 (iii)\u0915\u093e\u0930\u094d\u092f \u090a\u0930\u094d\u091c\u093e SI \u091c\u0942\u0932 \u0938\u0924\u094d\u092f (iv)\u0917\u0924\u093f\u0939\u0940\u0928 \u0916\u093f\u0902\u091a\u0940 \u0930\u092c\u0930 \u092c\u0948\u0902\u0921 \u092e\u0947\u0902 \u0917\u0924\u093f\u091c \u0905\u0938\u0924\u094d\u092f \u0938\u094d\u0925\u093f\u0924\u093f\u091c (v)\u090a\u0930\u094d\u091c\u093e \u090f\u0915 \u0930\u0942\u092a \u0926\u0942\u0938\u0930\u0947 \u092e\u0947\u0902 \u092c\u0926\u0932 \u0938\u0915\u0924\u0940 \u0938\u0924\u094d\u092f - \u0916\u093e\u0932\u0940 \u091c\u0917\u0939 (i)\u0915\u093e\u0930\u094d\u092f=\u092c\u0932\u00d7\u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928 \u092c\u0932 \u0926\u093f\u0936\u093e \u092e\u0947\u0902 Eq7.2 (ii)1 \u091c\u0942\u0932 \u091c\u092c1 \u0928\u094d\u092f\u0942\u091f\u0928 \u092c\u0932 1m \u0939\u091f\u093e\u090f \u0926\u093f\u0936\u093e \u092e\u0947\u0902 1J=1N\u00d71m (iii)\u0917\u0924\u093f\u091c \u00bdmv\u00b2 Eq7.6 (iv)\u0938\u094d\u0925\u093f\u0924\u093f\u091c mgh Eq7.8 (v)\u0936\u0915\u094d\u0924\u093f \u0926\u0930 \u091c\u093f\u0938 \u092a\u0930 \u0915\u093e\u0930\u094d\u092f \u0915\u093f\u092f\u093e \u091c\u093e\u0924\u093e P=W\/t Eq7.11 B) \u0938\u092d\u0940 \u0938\u0924\u094d\u092f C) \u0938\u092d\u0940 \u0905\u0938\u0924\u094d\u092f D) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A)<\/b><br><br>\n\n<b>Q23. \u0917\u0947\u0902\u0926 \u0909\u091a\u094d\u091a\u0924\u092e \u092c\u093f\u0902\u0926\u0941 \u092a\u0930 \u0915\u094c\u0928 \u0938\u093e \u0938\u0939\u0940? [\u092a\u0947\u091c 137 \u092a\u094d\u0930\u0936\u094d\u09283]<\/b><br>\nA) \u0917\u0947\u0902\u0926 \u090a\u092a\u0930 \u092b\u0947\u0902\u0915\u0940 \u0909\u091a\u094d\u091a\u0924\u092e \u092c\u093f\u0902\u0926\u0941 (i)\u092c\u0932 \u0936\u0942\u0928\u094d\u092f \u0917\u0932\u0924 mg \u0928\u0940\u091a\u0947 (ii)\u0924\u094d\u0935\u0930\u0923 \u0936\u0942\u0928\u094d\u092f \u0917\u0932\u0924 g10m\/s\u00b2 \u0928\u0940\u091a\u0947 (iii)\u0917\u0924\u093f\u091c \u0936\u0942\u0928\u094d\u092f \u0938\u0939\u0940 v0 K0 (iv)\u0938\u094d\u0925\u093f\u0924\u093f\u091c \u0905\u0927\u093f\u0915\u0924\u092e \u0938\u0939\u0940 U=mgh \u0905\u0927\u093f\u0915\u0924\u092e - \u0938\u0939\u0940 (iii)(iv) B) \u0915\u0947\u0935\u0932 (i) C) \u0915\u0947\u0935\u0932 (ii) D) \u0915\u0947\u0935\u0932 (iii)<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A) (iii)(iv)<\/b><br><br>\n\n<b>Q24. 9 \u0938\u094d\u0925\u093f\u0924\u093f\u092f\u094b\u0902 \u092e\u0947\u0902 \u090a\u0930\u094d\u091c\u093e \u0930\u0942\u092a\u093e\u0902\u0924\u0930\u0923? [\u092a\u0947\u091c 137 \u092a\u094d\u0930\u0936\u094d\u09284]<\/b><br>\nA) (i)\u091f\u094d\u0930\u0915 \u092a\u0939\u093e\u0921\u093c\u0940 \u090a\u092a\u0930 \u0930\u093e\u0938\u093e\u092f\u0928\u093f\u0915 \u0908\u0902\u0927\u0928\u2192\u0917\u0924\u093f\u091c+\u0938\u094d\u0925\u093f\u0924\u093f\u091c+\u090a\u0937\u094d\u092e\u0940\u092f (ii)\u0918\u0921\u093c\u0940 \u0938\u094d\u092a\u094d\u0930\u093f\u0902\u0917 \u0916\u0941\u0932\u0928\u093e \u0938\u094d\u0925\u093f\u0924\u093f\u091c \u092a\u094d\u0930\u0924\u094d\u092f\u093e\u0938\u094d\u0925\u2192\u0917\u0924\u093f\u091c+\u0927\u094d\u0935\u0928\u093f (iii)\u0939\u0930\u0947 \u092a\u0924\u094d\u0924\u094b\u0902 \u092a\u094d\u0930\u0915\u093e\u0936 \u0938\u0902\u0936\u094d\u0932\u0947\u0937\u0923 \u092a\u094d\u0930\u0915\u093e\u0936\u2192\u0930\u093e\u0938\u093e\u092f\u0928\u093f\u0915 (iv)\u092c\u093e\u0901\u0927 \u0938\u0947 \u092a\u093e\u0928\u0940 \u0938\u094d\u0925\u093f\u0924\u093f\u091c mgh\u2192\u0917\u0924\u093f\u091c\u2192\u0935\u093f\u0926\u094d\u092f\u0941\u0924 \u091a\u093f\u0924\u094d\u09307.36 \u0918\u0930\u093e\u091f \u092a\u0902\u091a\u0915\u094d\u0915\u0940 (v)\u092e\u093e\u091a\u093f\u0938 \u091c\u0932\u0928\u093e \u0930\u093e\u0938\u093e\u092f\u0928\u093f\u0915\u2192\u090a\u0937\u094d\u092e\u093e+\u092a\u094d\u0930\u0915\u093e\u0936 (vi)\u092a\u091f\u093e\u0916\u093e \u092b\u091f\u0928\u093e \u0930\u093e\u0938\u093e\u092f\u0928\u093f\u0915\u2192\u090a\u0937\u094d\u092e\u093e+\u092a\u094d\u0930\u0915\u093e\u0936+\u0927\u094d\u0935\u0928\u093f+\u0917\u0924\u093f\u091c (vii)\u092e\u093e\u0907\u0915\u094d\u0930\u094b\u092b\u094b\u0928 \u092c\u094b\u0932\u0928\u093e \u0927\u094d\u0935\u0928\u093f\u2192\u0935\u093f\u0926\u094d\u092f\u0941\u0924 (viii)\u091a\u092e\u0915\u0924\u093e \u092c\u0932\u094d\u092c \u0935\u093f\u0926\u094d\u092f\u0941\u0924\u2192\u092a\u094d\u0930\u0915\u093e\u0936+\u090a\u0937\u094d\u092e\u0940\u092f (ix)\u0938\u094b\u0932\u0930 \u092a\u0948\u0928\u0932 \u092a\u094d\u0930\u0915\u093e\u0936\u2192\u0935\u093f\u0926\u094d\u092f\u0941\u0924 B) \u0915\u0947\u0935\u0932 \u092c\u093e\u0901\u0927 C) \u0915\u0947\u0935\u0932 \u092c\u0932\u094d\u092c D) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A)<\/b><br><br>\n\n<b>Q25. \u092a\u0928\u091a\u0915\u094d\u0915\u0940 \u0918\u0930\u093e\u091f \u0915\u094d\u092f\u093e \u0939\u0948? [\u092a\u0947\u091c 136 \u091a\u093f\u0924\u094d\u0930 7.36 \u0938\u092e\u093e\u091c \u0938\u0947 \u091c\u094b\u0921\u093c \u0938\u093e\u0930\u093e\u0902\u0936]<\/b><br>\nA) \u091a\u093f\u0924\u094d\u09307.36 \u092a\u0928\u091a\u0915\u094d\u0915\u0940 \u0918\u0930\u093e\u091f \u092a\u0902\u091a\u0915\u094d\u0915\u0940 \u0939\u093f\u092e\u093e\u0932\u092f \u0915\u094d\u0937\u0947\u0924\u094d\u0930 \u092a\u093e\u0928\u0940 \u0928\u0940\u091a\u0947 \u092c\u0939\u0924\u093e \u0938\u094d\u0925\u093f\u0924\u093f\u091c\u2192\u0917\u0924\u093f\u091c \u092a\u093e\u0930\u0902\u092a\u0930\u093f\u0915 \u0918\u0930\u093e\u091f \u092a\u0902\u091a\u0915\u094d\u0915\u0940 \u0905\u0928\u093e\u091c \u092a\u0940\u0938\u0928\u0947 \u091a\u0915\u094d\u0915\u0940 \u092a\u0939\u093e\u0921\u093c\u0940 \u0915\u094d\u0937\u0947\u0924\u094d\u0930\u094b\u0902 \u092e\u0947\u0902 \u0905\u092d\u0940 \u092d\u0940 \u092a\u093e\u0928\u0940 \u090a\u092a\u0930 \u0938\u0947 \u0938\u094d\u0925\u093f\u0924\u093f\u091c \u0928\u0940\u091a\u0947 \u0906\u0924\u0947 \u092a\u093e\u0907\u092a A \u092e\u0947\u0902 \u0917\u0924\u093f\u091c \u092e\u0947\u0902 \u092c\u0926\u0932 \u0917\u0924\u093f\u091c \u092a\u0939\u093f\u092f\u093e B \u0918\u0942\u0930\u094d\u0923\u0928 \u092a\u0939\u093f\u092f\u093e \u092a\u0940\u0938\u0928\u0947 \u0935\u093e\u0932\u0947 \u092a\u0924\u094d\u0925\u0930 \u090a\u092a\u0930 C \u0938\u0947 \u091c\u0941\u0921\u093c\u093e \u0906\u0927\u0941\u0928\u093f\u0915 \u0938\u092e\u092f \u092e\u0947\u0902 \u092c\u093e\u0901\u0927\u094b\u0902 \u092e\u0947\u0902 \u091c\u092e\u093e \u092a\u093e\u0928\u0940 \u0938\u094d\u0925\u093f\u0924\u093f\u091c \u0917\u0924\u093f\u091c \u092e\u0947\u0902 \u092c\u0926\u0932 \u092c\u093f\u091c\u0932\u0940 \u0909\u0924\u094d\u092a\u093e\u0926\u0928 - \u0938\u093e\u0930\u093e\u0902\u0936 \u0915\u093e\u0930\u094d\u092f \u092c\u0932 \u0935\u0938\u094d\u0924\u0941 \u0939\u091f\u093e\u090f \u0926\u093f\u0936\u093e \u092e\u0947\u0902, \u0915\u094d\u0937\u092e\u0924\u093e \u0915\u093e\u0930\u094d\u092f \u0915\u0930\u0928\u0947 \u0915\u0940 \u090a\u0930\u094d\u091c\u093e, \u0915\u093e\u0930\u094d\u092f-\u090a\u0930\u094d\u091c\u093e \u0915\u093e\u0930\u094d\u092f=\u090a\u0930\u094d\u091c\u093e \u092a\u0930\u093f\u0935\u0930\u094d\u0924\u0928, \u0917\u0924\u093f \u0915\u0947 \u0915\u093e\u0930\u0923 \u0917\u0924\u093f\u091c K, \u0935\u093f\u0930\u0942\u092a\u0923 \u0938\u093e\u092a\u0947\u0915\u094d\u0937 \u0938\u094d\u0925\u093f\u0924\u093f \u0915\u0947 \u0915\u093e\u0930\u0923 \u0938\u094d\u0925\u093f\u0924\u093f\u091c, \u0936\u0915\u094d\u0924\u093f \u0926\u0930 \u0915\u093e\u0930\u094d\u092f \u0915\u0930\u0928\u0947 \u0915\u0940, \u0938\u0930\u0932 \u092e\u0936\u0940\u0928\u0947\u0902 \u0915\u093e\u0930\u094d\u092f \u0906\u0938\u093e\u0928 \u092a\u0930\u093f\u092e\u093e\u0923 \u0926\u093f\u0936\u093e \u092c\u0926\u0932 \u0915\u0941\u0932 \u0915\u093e\u0930\u094d\u092f \u0915\u092e \u0928\u0939\u0940\u0902 B) \u0915\u0947\u0935\u0932 \u0938\u094d\u0925\u093f\u0924\u093f\u091c C) \u0915\u0947\u0935\u0932 \u0917\u0924\u093f\u091c D) \u0915\u094b\u0908 \u0928\u0939\u0940\u0902<br>\n<b>\u0909\u0924\u094d\u0924\u0930: A)<\/b><br><br>\n\n<div style=\"background:#fff9c4;border:3px solid #fbc02d;padding:10px;border-radius:10px;text-align:center;font-weight:bold;\">\n\u2705 \u0936\u0941\u0926\u094d\u0927 \u0939\u093f\u0902\u0926\u0940 \u091f\u094d\u0930\u093f\u0915 Chapter7 \u2705<br>\n\u0915\u093e\u0930\u094d\u092f W=F\u00d7s 1J=1N\u00d71m Fig7.4 10J \u0936\u0942\u0928\u094d\u092f F0 s0 \u0932\u0902\u092c\u0935\u0924 Fig7.5 Fig7.6 \u0927\u0928\u093e\u0924\u094d\u092e\u0915 same \u0935\u094d\u0939\u0940\u0932\u091a\u0947\u092f\u0930 \u090b\u0923\u093e\u0924\u094d\u092e\u0915 opposite \u0917\u094b\u0932\u0915\u0940\u092a\u0930 -30J<br>\n\u0915\u093e\u0930\u094d\u092f=\u090a\u0930\u094d\u091c\u093e \u092a\u0930\u093f\u0935\u0930\u094d\u0924\u0928 Eq7.3 \u0915\u094d\u0937\u092e\u0924\u093e \u090a\u0930\u094d\u091c\u093e K=\u00bdmv\u00b2 Eq7.6 double 4\u00d7 184.9J \u091c\u0947\u091f 70m\/s 252km\/h U=mgh Eq7.8 20J \u0938\u0902\u0930\u0915\u094d\u0937\u0923 mgh v=\u221a2gh \u0935\u091c\u0928 \u0928\u0939\u0940\u0902 \u0930\u0948\u0902\u092a 20m P=W\/t Eq7.11 300W 20000W 1hp746W<br>\nMA=\u092d\u093e\u0930\/\u092a\u094d\u0930\u092f\u093e\u0938 Eq7.12 \u0918\u093f\u0930\u0928\u0940 MA1 \u0926\u093f\u0936\u093e \u092c\u0926\u0932 \u091a\u0932 MA>1 \u0932\u093f\u092b\u094d\u091f \u0915\u094d\u0930\u0947\u0928 \u0906\u0928\u0924 \u0924\u0932 MA=L\/h 1.67 \u0915\u093e\u0930\u094d\u092f same \u092c\u0932 \u0918\u091f\u093e \u0935\u093f\u0938\u094d\u0925\u093e\u092a\u0928 \u092c\u0922\u093c\u093e \u0909\u0924\u094d\u0924\u094b\u0932\u0915 F1d1=F2d2 n1L1=n2L2 MA=\u092a\u094d\u0930\u092f\u093e\u0938 \u092d\u0941\u091c\u093e\/\u092d\u093e\u0930 \u092d\u0941\u091c\u093e \u0935\u0930\u094d\u0917 I \u0906\u0932\u0902\u092c \u092c\u0940\u091a \u0915\u0948\u0902\u091a\u0940 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