Cơ năng (dễ)

Home Lớp 9 Khoa học tự nhiên 9 - sách kết nối tri thức Bài 3: Cơ năngBài tập cơ bản

{"common":{"save":0,"post_id":"8302","level":1,"total":10,"point":10,"point_extra":0},"segment":[{"id":"9567","post_id":"8302","mon_id":"1159533","chapter_id":"1159535","question":"C\u01a1 n\u0103ng là gì?<\/p>","options":["A. N\u0103ng l\u01b0\u1ee3ng c\u1ee7a v\u1eadt khi chuy\u1ec3n \u0111\u1ed9ng","B. N\u0103ng l\u01b0\u1ee3ng c\u1ee7a v\u1eadt do th\u1ebf n\u0103ng và \u0111\u1ed9ng n\u0103ng","C. N\u0103ng l\u01b0\u1ee3ng ch\u1ec9 liên quan \u0111\u1ebfn v\u1eadt \u0111\u1ee9ng yên","D. N\u0103ng l\u01b0\u1ee3ng do s\u1ef1 t\u01b0\u01a1ng tác gi\u1eefa các v\u1eadt"],"correct":"2","level":"1","hint":"","answer":"\u0110áp án: B. N\u0103ng l\u01b0\u1ee3ng c\u1ee7a v\u1eadt do th\u1ebf n\u0103ng và \u0111\u1ed9ng n\u0103ng Gi\u1ea3i thích:<\/p>C\u01a1 n\u0103ng là t\u1ed5ng h\u1ee3p c\u1ee7a \u0111\u1ed9ng n\u0103ng và th\u1ebf n\u0103ng. \u0110\u1ed9ng n\u0103ng là n\u0103ng l\u01b0\u1ee3ng c\u1ee7a v\u1eadt khi chuy\u1ec3n \u0111\u1ed9ng, còn th\u1ebf n\u0103ng là n\u0103ng l\u01b0\u1ee3ng do v\u1ecb trí c\u1ee7a v\u1eadt (ví d\u1ee5, v\u1eadt n\u1eb1m \u1edf \u0111\u1ed9 cao nh\u1ea5t \u0111\u1ecbnh).  <\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"125","test":"0","date":"2025-01-01 17:18:49","option_type":"txt","len":3},{"id":"9568","post_id":"8302","mon_id":"1159533","chapter_id":"1159535","question":"\u0110\u1ed9ng n\u0103ng c\u1ee7a m\u1ed9t v\u1eadt ph\u1ee5 thu\u1ed9c vào y\u1ebfu t\u1ed1 nào?<\/p>","options":["A. Ch\u1ec9 ph\u1ee5 thu\u1ed9c vào kh\u1ed1i l\u01b0\u1ee3ng c\u1ee7a v\u1eadt","B. Ch\u1ec9 ph\u1ee5 thu\u1ed9c vào v\u1eadn t\u1ed1c c\u1ee7a v\u1eadt","C. Ph\u1ee5 thu\u1ed9c vào kh\u1ed1i l\u01b0\u1ee3ng và v\u1eadn t\u1ed1c c\u1ee7a v\u1eadt","D. Ph\u1ee5 thu\u1ed9c vào nhi\u1ec7t \u0111\u1ed9 c\u1ee7a v\u1eadt"],"correct":"3","level":"1","hint":"","answer":"\u0110áp án: C. Ph\u1ee5 thu\u1ed9c vào kh\u1ed1i l\u01b0\u1ee3ng và v\u1eadn t\u1ed1c c\u1ee7a v\u1eadt<\/p>Gi\u1ea3i thích:<\/p>\u0110\u1ed9ng n\u0103ng c\u1ee7a v\u1eadt \u0111\u01b0\u1ee3c tính theo công th\u1ee9c $W_\u0111 = {1 \\over 2}mv^2$<\/span><\/p>Trong \u0111ó:<\/p>- $m$<\/span>: kh\u1ed1i l\u01b0\u1ee3ng c\u1ee7a v\u1eadt<\/p>- $v$<\/span>: v\u1eadn t\u1ed1c c\u1ee7a v\u1eadt.<\/p>Nh\u01b0 v\u1eady, \u0111\u1ed9ng n\u0103ng ph\u1ee5 thu\u1ed9c vào c\u1ea3 kh\u1ed1i l\u01b0\u1ee3ng và v\u1eadn t\u1ed1c.<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"125","test":"0","date":"2025-01-01 17:21:41","option_type":"txt","len":3},{"id":"9569","post_id":"8302","mon_id":"1159533","chapter_id":"1159535","question":"Th\u1ebf n\u0103ng c\u1ee7a v\u1eadt ph\u1ee5 thu\u1ed9c vào y\u1ebfu t\u1ed1 nào sau \u0111ây?<\/p>","options":["A. Chuy\u1ec3n \u0111\u1ed9ng c\u1ee7a v\u1eadt","B. V\u1ecb trí c\u1ee7a v\u1eadt trong l\u1ef1c tr\u01b0\u1eddng ","C. S\u1ef1 bi\u1ebfn d\u1ea1ng c\u1ee7a v\u1eadt","D. Nhi\u1ec7t \u0111\u1ed9 c\u1ee7a v\u1eadt"],"correct":"2","level":"1","hint":"","answer":"\u0110áp án: B. V\u1ecb trí c\u1ee7a v\u1eadt trong l\u1ef1c tr\u01b0\u1eddng  Gi\u1ea3i thích: Th\u1ebf n\u0103ng là n\u0103ng l\u01b0\u1ee3ng c\u1ee7a v\u1eadt do v\u1ecb trí c\u1ee7a nó trong m\u1ed9t tr\u01b0\u1eddng l\u1ef1c, ch\u1eb3ng h\u1ea1n nh\u01b0 tr\u1ecdng l\u1ef1c. V\u1eadt càng cao, th\u1ebf n\u0103ng càng l\u1edbn.  <\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"125","test":"0","date":"2025-01-01 17:25:01","option_type":"txt","len":2}]}