Một số ví dụ về cách giải các bài toán thuộc phần động lực học

Home Lớp 10 Vật lý 10 - Sách kết nối tri thức Bài 20. Một số ví dụ về cách giải các bài toán thuộc phần động lực họcBài tập cơ bản

{"common":{"save":0,"post_id":"8534","level":1,"total":10,"point":10,"point_extra":0},"segment":[{"id":"7753","mon_id":"1158790","chapter_id":"1158796","post_id":"8534","question":"S\u1eafp x\u1ebfp các b\u01b0\u1edbc \u0111\u1ec3 gi\u1ea3i m\u1ed9t bài toán thu\u1ed9c ph\u1ea7n \u0111\u1ed9ng l\u1ef1c h\u1ecdc:<\/p>(1) Bi\u1ec3u di\u1ec5n các l\u1ef1c tác d\u1ee5ng lên v\u1eadt. (2) Ch\u1ecdn v\u1eadt kh\u1ea3o sát chuy\u1ec3n \u0111\u1ed9ng. (3) Ch\u1ecdn tr\u1ee5c to\u1ea1 \u0111\u1ed9 Oxy. (4) Gi\u1ea3i ph\u01b0\u01a1ng trình tìm \u1ea9n. (5) Áp d\u1ee5ng \u0111\u1ecbnh lu\u1eadt II Newton.<\/p>","options":["A.<\/strong> (2), (1), (3), (5), (4).","B.<\/strong> (1), (2), (3), (5), (4).","C.<\/strong> (2), (1), (4), (5), (3).","D.<\/strong> (5), (1), (3), (2), (4)."],"correct":"1","level":"1","hint":"","answer":"Ch\u1ecdn A.<\/strong> (2), (1), (3), (5), (4).<\/span><\/p>Các b\u01b0\u1edbc \u0111\u1ec3 gi\u1ea3i m\u1ed9t bài toán thu\u1ed9c ph\u1ea7n \u0111\u1ed9ng l\u1ef1c h\u1ecdc: (2) Ch\u1ecdn v\u1eadt kh\u1ea3o sát chuy\u1ec3n \u0111\u1ed9ng. (1) Bi\u1ec3u di\u1ec5n các l\u1ef1c tác d\u1ee5ng lên v\u1eadt. (3) Ch\u1ecdn tr\u1ee5c to\u1ea1 \u0111\u1ed9 Oxy. (5) Áp d\u1ee5ng \u0111\u1ecbnh lu\u1eadt II Newton. (4) Gi\u1ea3i ph\u01b0\u01a1ng trình tìm \u1ea9n.<\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2025-02-26 08:38:45","option_type":"txt","len":2},{"id":"7754","mon_id":"1158790","chapter_id":"1158796","post_id":"8534","question":"D\u01b0\u1edbi tác d\u1ee5ng c\u1ee7a l\u1ef1c kéo F, m\u1ed9t v\u1eadt kh\u1ed1i l\u01b0\u1ee3ng 200 kg, b\u1eaft \u0111\u1ea7u chuy\u1ec3n \u0111\u1ed9ng nhanh d\u1ea7n \u0111\u1ec1u và sau khi \u0111i \u0111\u01b0\u1ee3c quãng \u0111\u01b0\u1eddng dài 10 m thì \u0111\u1ea1t v\u1eadn t\u1ed1c 25,2 km\/h. L\u1ef1c kéo tác d\u1ee5ng vào v\u1eadt có giá tr\u1ecb:<\/p>","options":["A.<\/strong> 245 N.","B.<\/strong> 490 N.","C.<\/strong> 940 N.","D.<\/strong> 294 N."],"correct":"2","level":"1","hint":"S\u1eed d\u1ee5ng công th\u1ee9c: $a=\\dfrac{v^2-v_0^2}{2s}$<\/span> ; $F=ma$<\/span>.<\/p>","answer":"Ch\u1ecdn B.<\/strong> 490 N.<\/span><\/p>Ta có: $a=\\dfrac{v^2-v_0^2}{2s}=\\dfrac{7^2-0}{2.10}=2,45\\;(m\/s^2)$<\/span>.<\/p>L\u1ef1c tác d\u1ee5ng lên v\u1eadt là: F = ma = 200 . 2,45 = 490 N.<\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2025-02-26 08:48:16","option_type":"txt","len":0},{"id":"7756","mon_id":"1158790","chapter_id":"1158796","post_id":"8534","question":"Khi ch\u1ecdn h\u1ec7 tr\u1ee5c to\u1ea1 \u0111\u1ed9 Ox và Oy c\u1ea7n chú ý \u0111i\u1ec1u gì?<\/p>","options":["A. <\/strong>Ch\u1ecdn tr\u1ee5c Ox trùng v\u1edbi h\u01b0\u1edbng chuy\u1ec3n \u0111\u1ed9ng c\u1ee7a v\u1eadt hay cùng h\u01b0\u1edbng v\u1edbi l\u1ef1c kéo khi v\u1eadt \u0111\u1ee9ng yên.","B.<\/strong> Ch\u1ecdn tr\u1ee5c Oy trùng v\u1edbi h\u01b0\u1edbng chuy\u1ec3n \u0111\u1ed9ng.","C.<\/strong> Ch\u1ecdn tr\u1ee5c Ox ng\u01b0\u1ee3c v\u1edbi h\u01b0\u1edbng chuy\u1ec3n \u0111\u1ed9ng hay ng\u01b0\u1ee3c h\u01b0\u1edbng v\u1edbi l\u1ef1c kéo khi v\u1eadt \u0111\u1ee9ng yên.","D. <\/strong>Ch\u1ecdn tr\u1ee5c Oy theo ph\u01b0\u01a1ng c\u1ee7a tr\u1ecdng l\u1ef1c."],"correct":"1","level":"1","hint":"","answer":"Ch\u1ecdn A. <\/strong>Ch\u1ecdn tr\u1ee5c Ox trùng v\u1edbi h\u01b0\u1edbng chuy\u1ec3n \u0111\u1ed9ng c\u1ee7a v\u1eadt hay cùng h\u01b0\u1edbng v\u1edbi l\u1ef1c kéo khi v\u1eadt \u0111\u1ee9ng yên.<\/span><\/p>Khi ch\u1ecdn h\u1ec7 tr\u1ee5c to\u1ea1 \u0111\u1ed9 Ox và Oy c\u1ea7n chú ý ch\u1ecdn:<\/p>• Tr\u1ee5c Ox trùng v\u1edbi h\u01b0\u1edbng chuy\u1ec3n \u0111\u1ed9ng c\u1ee7a v\u1eadt hay cùng h\u01b0\u1edbng v\u1edbi l\u1ef1c kéo khi v\u1eadt \u0111\u1ee9ng yên.<\/p>• Tr\u1ee5c Oy vuông góc v\u1edbi m\u1eb7t ph\u1eb3ng ti\u1ebfp xúc c\u1ee7a v\u1eadt.<\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2025-02-26 08:51:10","option_type":"txt","len":3}]}