{"common":{"save":0,"post_id":"8777","level":2,"total":10,"point":10,"point_extra":0},"segment":[{"id":"8232","mon_id":"1158790","chapter_id":"1159772","post_id":"8777","question":"<p>M\u1ed9t v\u1eadt kh\u1ed1i l\u01b0\u1ee3ng 200 g có \u0111\u1ed9ng n\u0103ng là 10 J. L\u1ea5y g = 10 m\/s². Khi \u0111ó v\u1eadn t\u1ed1c c\u1ee7a v\u1eadt là:<\/p>","options":["<strong>A.<\/strong> 10 m\/s.","<strong>B.<\/strong> 100 m\/s.","<strong>C.<\/strong> 15 m\/s.","<strong>D.<\/strong> 20 m\/s."],"correct":"1","level":"2","hint":"","answer":"<p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>A.<\/strong> 10 m\/s.<\/span><\/p><p>\u0110\u1ed5i: 200 g = 0,2 kg.<\/p><p>Ta có: <span class=\"math-tex\">$W_\u0111=\\dfrac{1}{2}mv^2$<\/span> suy ra <span class=\"math-tex\">$v=\\sqrt{\\dfrac{2W_\u0111}{m}}=\\sqrt{\\dfrac{2.10}{0,2}}=10(m\/s)$<\/span>.<\/p><p>V\u1eady v\u1eadn t\u1ed1c c\u1ee7a v\u1eadt là 10 m\/s.<\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2025-04-07 09:34:56","option_type":"txt","len":1},{"id":"8233","mon_id":"1158790","chapter_id":"1159772","post_id":"8777","question":"<p>M\u1ed9t v\u1eadt kh\u1ed1i l\u01b0\u1ee3ng 2 kg có th\u1ebf n\u0103ng 8 J \u0111\u1ed1i v\u1edbi m\u1eb7t \u0111\u1ea5t. L\u1ea5y g = 10m\/s². Khi \u0111ó v\u1eadt \u1edf \u0111\u1ed9 cao<\/p>","options":["<strong>A.<\/strong> 1,0 m.","<strong>B.<\/strong> 0,4 m.","<strong>C.<\/strong> 9,8 m.","<strong>D.<\/strong> 32 m."],"correct":"2","level":"2","hint":"","answer":"<p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>B.<\/strong> 0,4 m.<\/span><\/p><p>Ch\u1ecdn m\u1ed1c tính th\u1ebf n\u0103ng \u1edf m\u1eb7t \u0111\u1ea5t.<\/p><p>Ta có: <span class=\"math-tex\">$W_t=mgh$<\/span> suy ra <span class=\"math-tex\">$h=\\dfrac{W_t}{mg}=\\dfrac{8}{10.2}=0,4(m)$<\/span>.<\/p><p>V\u1eady khi \u0111ó v\u1eadt \u1edf \u0111\u1ed9 cao 0,4 m.<\/p>","type":"choose","extra_type":"shape2","user_id":"131","test":"0","date":"2025-04-07 09:37:40","option_type":"txt","len":0},{"id":"8234","mon_id":"1158790","chapter_id":"1159772","post_id":"8777","question":"<p>Ch\u1ecdn ph\u01b0\u01a1ng án <strong>\u0111úng<\/strong>. \u0110ô\u0323ng n\u0103ng cu\u0309a mô\u0323t vâ\u0323t thay \u0111ô\u0309i khi v\u1eadt<\/p>","options":["<strong>A.<\/strong> chuyê\u0309n \u0111ô\u0323ng th\u0103\u0309ng \u0111ê\u0300u.","<strong>B.<\/strong> chuyê\u0309n \u0111ô\u0323ng tro\u0300n \u0111ê\u0300u.","<strong>C.<\/strong> chuyê\u0309n \u0111ô\u0323ng v\u1edbi v\u1eadn t\u1ed1c không \u0111\u1ed5i <span class=\"math-tex\">$v_o$<\/span>.","<strong>D.<\/strong> chuyê\u0309n \u0111ô\u0323ng biê\u0301n \u0111ô\u0309i \u0111ê\u0300u."],"correct":"4","level":"2","hint":"","answer":"<p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>D.<\/strong> chuyê\u0309n \u0111ô\u0323ng biê\u0301n \u0111ô\u0309i \u0111ê\u0300u.<\/span><\/p><p>Các ph\u01b0\u01a1ng án A, B, C – v\u1eadt có v\u1eadn t\u1ed1c không \u0111\u1ed5i ⇒ \u0110\u1ed9ng n\u0103ng c\u1ee7a v\u1eadt không \u0111\u1ed5i.<\/p><p>Ph\u01b0\u01a1ng án D - khi v\u1eadt chuy\u1ec3n \u0111\u1ed9ng bi\u1ebfn \u0111\u1ed5i \u0111\u1ec1u thì v\u1eadn t\u1ed1c c\u1ee7a v\u1eadt thay \u0111\u1ed5i (<span class=\"math-tex\">$v=v_o+at$<\/span>)<br \/>⇒ \u0110\u1ed9ng n\u0103ng c\u0169ng thay \u0111\u1ed5i do \u0111\u1ed9ng n\u0103ng t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi bình ph\u01b0\u01a1ng v\u1eadn t\u1ed1c.<\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2025-04-07 09:40:06","option_type":"math","len":0}]}
