{"segment":[{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":"Ng\u01b0\u1eddi ta \u0111\u01b0a m\u1ed9t v\u1eadt n\u1eb7ng l\u00ean \u0111\u1ed9 cao $h$ b\u1eb1ng hai c\u00e1ch. C\u00e1ch th\u1ee9 nh\u1ea5t, k\u00e9o tr\u1ef1c ti\u1ebfp v\u1eadt l\u00ean theo ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng. C\u00e1ch th\u1ee9 hai, k\u00e9o v\u1eadt theo m\u1eb7t ph\u1eb3ng nghi\u00eang c\u00f3 chi\u1ec1u d\u00e0i g\u1ea5p hai l\u1ea7n \u0111\u1ed9 cao $h$. N\u1ebfu b\u1ecf qua ma s\u00e1t \u1edf m\u1eb7t ph\u1eb3ng nghi\u00eang th\u00ec: ","select":["A. C\u00f4ng th\u1ef1c hi\u1ec7n \u1edf hai c\u00e1ch \u0111\u1ec1u nh\u01b0 nhau.","B. C\u00f4ng th\u1ef1c hi\u1ec7n \u1edf c\u00e1ch th\u1ee9 hai nh\u1ecf h\u01a1n v\u00ec l\u1ef1c k\u00e9o v\u1eadt theo m\u1eb7t ph\u1eb3ng nghi\u00eang nh\u1ecf h\u01a1n.","C. C\u00f4ng th\u1ef1c hi\u1ec7n \u1edf c\u00e1ch th\u1ee9 nh\u1ea5t l\u1edbn h\u01a1n v\u00ec l\u1ef1c k\u00e9o l\u1edbn h\u01a1n.","D. C\u00f4ng th\u1ef1c hi\u1ec7n \u1edf c\u00e1ch th\u1ee9 nh\u1ea5t nh\u1ecf h\u01a1n v\u00ec \u0111\u01b0\u1eddng \u0111i c\u1ee7a v\u1eadt ch\u1ec9 b\u1eb1ng n\u1eeda \u0111\u01b0\u1eddng \u0111i c\u1ee7a v\u1eadt \u1edf c\u00e1ch th\u1ee9 hai."],"hint":"","explain":"<span class='basic_left'>Theo \u0111\u1ecbnh lu\u1eadt v\u1ec1 c\u00f4ng th\u00ec kh\u00f4ng c\u00f3 m\u1ed9t m\u00e1y c\u01a1 \u0111\u01a1n gi\u1ea3n n\u00e0o cho ta l\u1ee3i v\u1ec1 c\u00f4ng n\u00ean c\u00f4ng th\u1ef1c hi\u1ec7n \u1edf hai c\u00e1ch \u0111\u1ec1u nh\u01b0 nhau. M\u1eb7t ph\u1eb3ng nghi\u00eang kh\u00f4ng gi\u00fap ta l\u1ee3i v\u1ec1 c\u00f4ng. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span><\/span> ","column":1}]}],"id_ques":2700},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":"M\u1ed9t ng\u01b0\u1eddi \u0111i xe \u0111\u1ea1p \u0111\u1ec1u t\u1eeb ch\u00e2n d\u1ed1c \u0111\u1ebfn \u0111\u1ec9nh d\u1ed1c cao $5m$. D\u1ed1c d\u00e0i $40m$. T\u00ednh c\u00f4ng do ng\u01b0\u1eddi \u0111\u00f3 sinh ra. Bi\u1ebft r\u1eb1ng l\u1ef1c ma s\u00e1t c\u1ea3n tr\u1edf xe chuy\u1ec3n \u0111\u1ed9ng tr\u00ean m\u1eb7t \u0111\u01b0\u1eddng l\u00e0 $20N$, ng\u01b0\u1eddi v\u00e0 xe c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng l\u00e0 $60kg$.","select":["A. 3600J","B. 3800J","C. 4000J","D. 4800J"],"hint":"","explain":"<span class='basic_left'>Tr\u1ecdng l\u01b0\u1ee3ng c\u1ee7a ng\u01b0\u1eddi v\u00e0 xe: $P = 60 . 10 = 600N$<br\/>L\u1ef1c ma s\u00e1t: ${{F}_{ms}} = 20N$.<br\/>V\u1eady c\u00f4ng hao ph\u00ed: ${{A}_{1}} = {{F}_{ms}} . S = 20 . 40 = 800J$<br\/>C\u00f4ng c\u00f3 \u00edch: ${{A}_{2}} = P . h = 600 .5 = 3000J$<br\/>C\u00f4ng c\u1ee7a ng\u01b0\u1eddi sinh ra: $A = {{A}_{1}} + {{A}_{2}} = 800 + 3000 = 3800J$<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":2}]}],"id_ques":2701},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":5,"ques":"M\u1ed9t ng\u01b0\u1eddi c\u00f4ng nh\u00e2n d\u00f9ng r\u00f2ng r\u1ecdc \u0111\u1ed9ng \u0111\u1ec3 n\u00e2ng 1 v\u1eadt l\u00ean cao 7m v\u1edbi l\u1ef1c k\u00e9o \u1edf \u0111\u1ea7u d\u00e2y t\u1ef1 do l\u00e0 160N. H\u1ecfi ng\u01b0\u1eddi c\u00f4ng nh\u00e2n \u0111\u00f3 ph\u1ea3i th\u1ef1c hi\u1ec7n m\u1ed9t c\u00f4ng b\u1eb1ng bao nhi\u00eau ?","select":["A. 2120J","B. 3440J","C. 2240J","D. 1240J"],"hint":"","explain":"<span class='basic_left'>K\u00e9o v\u1eadt l\u00ean cao b\u1eb1ng r\u00f2ng r\u1ecdc \u0111\u1ed9ng th\u00ec l\u1ee3i 2 l\u1ea7n v\u1ec1 l\u1ef1c, thi\u1ec7t 2 l\u1ea7n v\u1ec1 \u0111\u01b0\u1eddng \u0111i.<br\/>V\u1eadt n\u00e2ng l\u00ean 7m th\u00ec \u0111\u1ea7u d\u00e2y t\u1ef1 do ph\u1ea3i k\u00e9o 1 \u0111o\u1ea1n 14m <br\/>C\u00f4ng do ng\u01b0\u1eddi nh\u00e2n c\u00f4ng th\u1ef1c hi\u1ec7n:<br\/>$A = F . S = 160 . 14 = 2240 J$ <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":2}]}],"id_ques":2702},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[4]],"list":[{"point":5,"ques":"M\u1ed9t ng\u01b0\u1eddi \u0111\u01b0a m\u1ed9t v\u1eadt n\u1eb7ng l\u00ean cao $h$ b\u1eb1ng hai c\u00e1ch. C\u00e1c th\u1ee9 nh\u1ea5t, k\u00e9o tr\u1ef1c ti\u1ebfp v\u1eadt theo ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng. C\u00e1ch th\u1ee9 hai, k\u00e9o v\u1eadt d\u00f9ng r\u00f2ng r\u1ecdc \u0111\u1ed9ng. C\u00f4ng \u1edf tr\u01b0\u1eddng h\u1ee3p n\u00e0o l\u1edbn h\u01a1n? ","select":["A. C\u00f4ng th\u1ef1c hi\u1ec7n \u1edf c\u00e1ch th\u1ee9 hai l\u1edbn h\u01a1n v\u00ec \u0111\u01b0\u1eddng \u0111i l\u1edbn g\u1ea5p hai l\u1ea7n","B. C\u00f4ng th\u1ef1c hi\u1ec7n \u1edf c\u00e1ch th\u1ee9 hai nh\u1ecf h\u01a1n v\u00ec l\u1ef1c k\u00e9o v\u1eadt b\u1eb1ng r\u00f2ng r\u1ecdc nh\u1ecf h\u01a1n","C. C\u00f4ng th\u1ef1c hi\u1ec7n \u1edf c\u00e1ch th\u1ee9 nh\u1ea5t l\u1edbn h\u01a1n v\u00ec l\u1ef1c k\u00e9o l\u1edbn h\u01a1n","D. C\u00f4ng th\u1ef1c hi\u1ec7n \u1edf hai c\u00e1ch \u0111\u1ec1u nh\u01b0 nhau"],"hint":"","explain":"<span class='basic_left'>C\u00f4ng th\u1ef1c hi\u1ec7n \u1edf hai c\u00e1ch \u0111\u1ec1u nh\u01b0 nhau v\u00ec theo \u0111\u1ecbnh lu\u1eadt v\u1ec1 c\u00f4ng th\u00ec kh\u00f4ng c\u00f3 m\u1ed9t m\u00e1y c\u01a1 \u0111\u01a1n gi\u1ea3n n\u00e0o cho ta l\u1ee3i v\u1ec1 c\u00f4ng n\u00ean c\u00f4ng th\u1ef1c hi\u1ec7n \u1edf hai c\u00e1ch \u0111\u1ec1u nh\u01b0 nhau. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 D.<\/span><\/span> ","column":1}]}],"id_ques":2703},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":"Trong c\u00f4ng th\u1ee9c t\u00ednh hi\u1ec7u su\u1ea5t c\u1ee7a m\u1eb7t ph\u1eb3ng nghi\u00eang $H=\\dfrac{P\\times h}{F\\times L}\\times 100\\%$ th\u00ec F l\u00e0:","select":["A. L\u1ef1c k\u00e9o theo ph\u01b0\u01a1ng ngang.","B. L\u1ef1c k\u00e9o theo ph\u01b0\u01a1ng c\u1ee7a m\u1eb7t ph\u1eb3ng nghi\u00eang.","C. L\u1ef1c k\u00e9o theo ph\u01b0\u01a1ng vu\u00f4ng g\u00f3c v\u1edbi m\u1eb7t ph\u1eb3ng nghi\u00eang.","D. Tr\u1ecdng l\u1ef1c c\u1ee7a v\u1eadt."],"hint":"","explain":"<span class='basic_left'>Trong c\u00f4ng th\u1ee9c t\u00ednh hi\u1ec7u su\u1ea5t c\u1ee7a m\u1eb7t ph\u1eb3ng nghi\u00eang $H=\\dfrac{P\\times h}{F\\times L}\\times 100\\%$ th\u00ec F l\u00e0 l\u1ef1c k\u00e9o theo ph\u01b0\u01a1ng c\u1ee7a m\u1eb7t ph\u1eb3ng nghi\u00eang.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":1}]}],"id_ques":2704},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":"M\u1ed9t ng\u01b0\u1eddi n\u00e2ng m\u1ed9t v\u1eadt n\u1eb7ng l\u00ean c\u00f9ng m\u1ed9t \u0111\u1ed9 cao b\u1eb1ng hai c\u00e1ch: <br\/>C\u00e1ch th\u1ee9 nh\u1ea5t, k\u00e9o v\u1eadt b\u1eb1ng m\u1ed9t r\u00f2ng r\u1ecdc c\u1ed1 \u0111\u1ecbnh.<br\/>C\u00e1ch th\u1ee9 hai k\u1ebft h\u1ee3p m\u1ed9t r\u00f2ng r\u1ecdc c\u1ed1 \u0111\u1ecbnh v\u00e0 m\u1ed9t r\u00f2ng r\u1ecdc \u0111\u1ed9ng.<br\/> N\u1ebfu b\u1ecf qua tr\u1ecdng l\u01b0\u1ee3ng c\u1ee7a ma s\u00e1t v\u00e0 r\u00f2ng r\u1ecdc th\u00ec:","select":["A. C\u00f4ng th\u1ef1c hi\u1ec7n \u1edf hai c\u00e1ch \u0111\u1ec1u b\u1eb1ng nhau.","B. C\u00f4ng th\u1ef1c hi\u1ec7n \u1edf c\u00e1ch th\u1ee9 nh\u1ea5t l\u1edbn h\u01a1n v\u00ec l\u1ef1c k\u00e9o b\u1eb1ng tr\u1ecdng l\u01b0\u1ee3ng c\u1ee7a v\u1eadt.","C. C\u00f4ng th\u1ef1c hi\u1ec7n \u1edf c\u00e1ch th\u1ee9 hai l\u1edbn h\u01a1n v\u00ec ph\u1ea3i k\u00e9o d\u00e2y d\u00e0i h\u01a1n.","D. C\u00f4ng th\u1ef1c hi\u1ec7n \u1edf c\u00e1ch th\u1ee9 hai nh\u1ecf h\u01a1n v\u00ec ph\u1ea3i k\u00e9o nh\u1ecf h\u01a1n tr\u1ecdng l\u01b0\u1ee3ng c\u1ee7a v\u1eadt."],"hint":"","explain":"<span class='basic_left'>C\u00f4ng th\u1ef1c hi\u1ec7n \u1edf hai c\u00e1ch \u0111\u1ec1u nh\u01b0 nhau v\u00ec theo \u0111\u1ecbnh lu\u1eadt v\u1ec1 c\u00f4ng th\u00ec kh\u00f4ng c\u00f3 m\u1ed9t m\u00e1y c\u01a1 \u0111\u01a1n gi\u1ea3n n\u00e0o cho ta l\u1ee3i v\u1ec1 c\u00f4ng n\u00ean c\u00f4ng th\u1ef1c hi\u1ec7n \u1edf hai c\u00e1ch \u0111\u1ec1u nh\u01b0 nhau.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span><\/span> ","column":1}]}],"id_ques":2705},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":5,"ques":"Trong c\u00e1c ph\u00e1t bi\u1ec3u sau, ph\u00e1t bi\u1ec3u n\u00e0o \u0111\u00fang v\u1edbi \u0111\u1ecbnh lu\u1eadt v\u1ec1 c\u00f4ng: ","select":["A. C\u00e1c m\u00e1y c\u01a1 \u0111\u01a1n gi\u1ea3n \u0111\u1ec1u cho l\u1ee3i v\u1ec1 c\u00f4ng.","B. Kh\u00f4ng m\u1ed9t m\u00e1y c\u01a1 \u0111\u01a1n gi\u1ea3n n\u00e0o cho l\u1ee3i v\u1ec1 c\u00f4ng, m\u00e0 ch\u1ec9 l\u1ee3i v\u1ec1 l\u1ef1c v\u00e0 l\u1ee3i v\u1ec1 \u0111\u01b0\u1eddng \u0111i.","C. Kh\u00f4ng m\u1ed9t m\u00e1y c\u01a1 \u0111\u01a1n gi\u1ea3n n\u00e0o cho ta l\u1ee3i v\u1ec1 c\u00f4ng. \u0110\u01b0\u1ee3c l\u1ee3i bao nhi\u00eau l\u1ea7n v\u1ec1 l\u1ef1c th\u00ec thi\u1ec7t b\u1ea5y nhi\u00eau l\u1ea7n v\u1ec1 \u0111\u01b0\u1eddng \u0111i v\u00e0 ng\u01b0\u1ee3c l\u1ea1i.","D. C\u00e1c m\u00e1y c\u01a1 \u0111\u01a1n gi\u1ea3n \u0111\u1ec1u l\u1ee3i v\u1ec1 c\u00f4ng, trong \u0111\u00f3 l\u1ee3i c\u1ea3 v\u1ec1 l\u1ef1c l\u1eabn c\u1ea3 \u0111\u01b0\u1eddng \u0111i."],"hint":"","explain":"<span class='basic_left'>Kh\u00f4ng m\u1ed9t m\u00e1y c\u01a1 \u0111\u01a1n gi\u1ea3n n\u00e0o cho ta l\u1ee3i v\u1ec1 c\u00f4ng. \u0110\u01b0\u1ee3c l\u1ee3i bao nhi\u00eau l\u1ea7n v\u1ec1 l\u1ef1c th\u00ec thi\u1ec7t b\u1ea5y nhi\u00eau l\u1ea7n v\u1ec1 \u0111\u01b0\u1eddng \u0111i v\u00e0 ng\u01b0\u1ee3c l\u1ea1i. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":1}]}],"id_ques":2706},{"time":24,"part":[{"title":"","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":"Trong c\u00e1c ph\u00e1t bi\u1ec3u sau, ph\u00e1t bi\u1ec3u n\u00e0o sai ? ","select":["A. R\u00f2ng r\u1ecdc c\u1ed1 \u0111\u1ecbnh ch\u1ec9 c\u00f3 t\u00e1c d\u1ee5ng \u0111\u1ed5i h\u01b0\u1edbng c\u1ee7a l\u1ef1c v\u00e0 cho ta l\u1ee3i v\u1ec1 c\u00f4ng.","B. R\u00f2ng r\u1ecdc \u0111\u1ed9ng cho ta l\u1ee3i h\u1ea1i l\u1ea7n v\u1ec1 l\u1ef1c, thi\u1ec7t h\u1ea1i l\u1ea7n v\u1ec1 \u0111\u01b0\u1eddng \u0111i, kh\u00f4ng cho ta l\u1ee3i v\u1ec1 c\u00f4ng.","C. M\u1eb7t ph\u1eb3ng nghi\u00eang cho ta l\u1ee3i v\u1ec1 l\u1ef1c, thi\u1ec7t v\u1ec1 \u0111\u01b0\u1eddng \u0111i, kh\u00f4ng cho ta l\u1ee3i v\u1ec1 c\u00f4ng.","D. \u0110\u00f2n b\u1ea9y cho ta l\u1ee3i v\u1ec1 l\u1ef1c, thi\u1ec7t v\u1ec1 \u0111\u01b0\u1eddng \u0111i ho\u1eb7c ng\u01b0\u1ee3c l\u1ea1i, kh\u00f4ng cho ta l\u1ee3i v\u1ec1 c\u00f4ng."],"hint":"","explain":"<span class='basic_left'>R\u00f2ng r\u1ecdc c\u1ed1 \u0111\u1ecbnh ch\u1ec9 c\u00f3 t\u00e1c d\u1ee5ng \u0111\u1ed5i h\u01b0\u1edbng c\u1ee7a l\u1ef1c v\u00e0 kh\u00f4ng cho ta l\u1ee3i v\u1ec1 c\u00f4ng. V\u00ec kh\u00f4ng m\u1ed9t m\u00e1y c\u01a1 \u0111\u01a1n gi\u1ea3n n\u00e0o cho ta l\u1ee3i v\u1ec1 c\u00f4ng. \u0110\u01b0\u1ee3c l\u1ee3i bao nhi\u00eau l\u1ea7n v\u1ec1 l\u1ef1c th\u00ec thi\u1ec7t b\u1ea5y nhi\u00eau l\u1ea7n v\u1ec1 \u0111\u01b0\u1eddng \u0111i v\u00e0 ng\u01b0\u1ee3c l\u1ea1i.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span><\/span> ","column":1}]}],"id_ques":2707},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":"K\u00e9o \u0111\u1ec1u hai th\u00f9ng h\u00e0ng, m\u1ed7i th\u00f9ng n\u1eb7ng 500N l\u00ean s\u00e0n \u00f4 t\u00f4 c\u00e1ch m\u1eb7t \u0111\u1ea5t 1m b\u1eb1ng t\u1ea5m v\u00e1n \u0111\u1eb7t nghi\u00eang (ma s\u00e1t kh\u00f4ng \u0111\u00e1ng k\u1ec3). K\u00e9o th\u00f9ng th\u1ee9 nh\u1ea5t d\u00f9ng t\u1ea5m v\u00e1n 4m. K\u00e9o th\u00f9ng th\u1ee9 hai d\u00f9ng t\u1ea5m v\u00e1n 2m. Trong tr\u01b0\u1eddng h\u1ee3p n\u00e0o ng\u01b0\u1eddi ta k\u00e9o m\u1ed9t l\u1ef1c nh\u1ecf h\u01a1n v\u00e0 nh\u1ecf h\u01a1n bao nhi\u00eau l\u1ea7n? H\u00e3y ch\u1ecdn c\u00e2u \u0111\u00fang? ","select":["A. Tr\u01b0\u1eddng h\u1ee3p th\u1ee9 nh\u1ea5t l\u1ef1c k\u00e9o nh\u1ecf h\u01a1n v\u00e0 nh\u1ecf h\u01a1n 4 l\u1ea7n.","B. Tr\u01b0\u1eddng h\u1ee3p th\u1ee9 nh\u1ea5t l\u1ef1c k\u00e9o nh\u1ecf h\u01a1n v\u00e0 nh\u1ecf h\u01a1n 2 l\u1ea7n.","C. Tr\u01b0\u1eddng h\u1ee3p th\u1ee9 hai l\u1ef1c k\u00e9o nh\u1ecf h\u01a1n v\u00e0 nh\u1ecf h\u01a1n 2 l\u1ea7n.","D. Tr\u01b0\u1eddng h\u1ee3p th\u1ee9 hai l\u1ef1c k\u00e9o nh\u1ecf h\u01a1n v\u00e0 nh\u1ecf h\u01a1n 4 l\u1ea7n."],"hint":"","explain":"<span class='basic_left'>Theo \u0111\u1ecbnh lu\u1eadt b\u1ea3o to\u00e0n v\u1ec1 c\u00f4ng, tr\u01b0\u1eddng h\u1ee3p th\u1ee9 nh\u1ea5t b\u1ecb thi\u1ec7t 2 l\u1ea7n v\u1ec1 \u0111\u01b0\u1eddng \u0111i so v\u1edbi tr\u01b0\u1eddng h\u1ee3p th\u1ee9 hai, n\u00ean s\u1ebd \u0111\u01b0\u1ee3c l\u1ee3i h\u01a1n 2 l\u1ea7n v\u1ec1 l\u1ef1c so v\u1edbi tr\u01b0\u1eddng h\u1ee3p th\u1ee9 hai. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":1}]}],"id_ques":2708},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":5,"ques":"Ng\u01b0\u1eddi ta d\u00f9ng m\u1ed9t m\u1eb7t ph\u1eb3ng nghi\u00eang \u0111\u1ec3 k\u00e9o m\u1ed9t v\u1eadt c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 50kg l\u00ean cao 2m. N\u1ebfu kh\u00f4ng c\u00f3 ma s\u00e1t th\u00ec l\u1ef1c k\u00e9o l\u00e0 125N. Th\u1ef1c t\u1ebf c\u00f3 ma s\u00e1t v\u00e0 l\u1ef1c k\u1ebf l\u00e0 150N. Hi\u1ec7u su\u1ea5t c\u1ee7a m\u1eb7t ph\u1eb3ng nghi\u00eang d\u00f9ng \u1edf tr\u00ean l\u00e0 bao nhi\u00eau?","select":["A. H = 66,33%.","B. H = 66,67 %.","C. H = 83,33%.","D. H = 87,33 %."],"hint":"","explain":"<span class='basic_left'>Qu\u00e3ng \u0111\u01b0\u1eddng di chuy\u1ec3n tr\u00ean m\u1eb7t ph\u1eb1ng nghi\u00eang l\u00e0:<br\/>$S=\\dfrac{P\\times h}{F}=\\dfrac{50\\times 10\\times 2}{125}=8m$ <br\/>C\u00f4ng c\u00f3 \u00edch l\u00e0:<br\/>${{A}_{ci}}=P\\times h=50\\times 10\\times 2=1000Nm$ <br\/>C\u00f4ng to\u00e0n ph\u1ea7n:<br\/>${{A}_{tp}}={{F}_{keo}}\\times S=150\\times 8=1200Nm$ <br\/>Hi\u1ec7u su\u1ea5t: $H=\\dfrac{1000}{1200}=83,33\\%$<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":2}]}],"id_ques":2709},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[4]],"list":[{"point":5,"ques":"\u0110\u1ec3 \u0111\u01b0a v\u1eadt c\u00f3 tr\u1ecdng l\u01b0\u1ee3ng P = 420N l\u00ean cao b\u1eb1ng r\u00f2ng r\u1ecdc \u0111\u1ed9ng ph\u1ea3i k\u00e9o d\u00e2y \u0111i m\u1ed9t \u0111o\u1ea1n 8m. L\u1ef1c k\u00e9o, \u0111\u1ed9 cao \u0111\u01b0a v\u1eadt l\u00ean v\u00e0 c\u00f4ng n\u00e2ng v\u00e2t l\u00ean l\u00e0 bao nhi\u00eau?","select":["A. $F = 210N ; h = 8 m ; A = 1680 J$.","B. $F = 420N ; h = 4 m ; A = 1680 J$.","C. $F = 210N ; h = 4 m ; A = 16800 J$.","D. $F = 210N ; h = 4 m ; A = 1680 J$."],"hint":"","explain":"<span class='basic_left'>G\u1ecdi l\u1ef1c k\u00e9o l\u00e0 F, \u0111\u1ed9 cao \u0111\u01b0a v\u1eadt l\u00ean l\u00e0 h, v\u00e0 c\u00f4ng n\u00e2ng v\u00e2t l\u00ean l\u00e0 A.<br\/>Theo \u0111\u1ecbnh lu\u1eadt b\u1ea3o to\u00e0n c\u00f4ng ta c\u00f3:<br\/>$A=P\\times h=F\\times S$<br\/> N\u00ean \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 D.<br\/>Ta c\u00f3: $1680=420\\times 4=210\\times 8$<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 D.<\/span><\/span> ","column":2}]}],"id_ques":2710},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":"Ng\u01b0\u1eddi ta d\u00f9ng m\u1ed9t l\u1ef1c 400N k\u00e9o m\u1ed9t v\u1eadt 75kg l\u00ean nh\u1edd m\u1eb7t ph\u1eb3ng nghi\u00eang d\u00e0i 3,5 m, cao 0,8m. Hi\u1ec7u su\u1ea5t c\u1ea3 m\u1eb7t ph\u1eb3ng nghi\u00eang c\u00f3 th\u1ec3 nh\u1eadn gi\u00e1 tr\u1ecb n\u00e0o sau \u0111\u00e2y: ","select":["A. $H = 22,86 \\%$.","B. $H = 42,86 \\%$.","C. $H = 32,86 \\%$.","D. $H = 52,86 \\%$."],"hint":"","explain":"<span class='basic_left'>C\u00f4ng k\u00e9o v\u1eadt tr\u00ean m\u1eb7t ph\u1eb3ng nghi\u00eang: ${{A}_{1}}=3,5\\times 400=1400J$<br\/> C\u00f4ng c\u1ee7a tr\u1ecdng l\u1ef1c l\u00e0: ${{A}_{2}}=75\\times 10\\times 0,8=600J$<br\/>Hi\u1ec7u su\u1ea5t l\u00e0 $H=\\dfrac{{{A}_{2}}}{{{A}_{1}}}=\\dfrac{600}{1400}=42,86\\%$ <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":2}]}],"id_ques":2711},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":"Ng\u01b0\u1eddi ta k\u00e9o v\u1eadt c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng $m =45$kg l\u00ean m\u1eb7t ph\u1eb3ng nghi\u00eang d\u00e0i 16m, cao 1,5m. L\u1ef1c c\u1ea3n do ma s\u00e1t l\u00e0 $F = 24N$. Coi v\u1eadt chuy\u1ec3n \u0111\u1ed9ng \u0111\u1ec1u. C\u00f4ng c\u1ee7a ng\u01b0\u1eddi k\u00e9o c\u00f3 th\u1ec3 nh\u1eadn gi\u00e1 tr\u1ecb n\u00e0o sau: ","select":["A. $A = 1590J$.","B. $A = 1059J$.","C. $A = 10590J$.","D. M\u1ed9t gi\u00e1 tr\u1ecb kh\u00e1c."],"hint":"","explain":"<span class='basic_left'>C\u00f4ng c\u1ee7a l\u1ef1c ma s\u00e1t: ${{A}_{{{F}_{ms}}}}=24\\times 16=384J$ <br\/>C\u00f4ng c\u1ee7a tr\u1ecdng l\u1ef1c l\u00e0: ${{A}_{P}}=45\\times 10\\times 1,5=675J$ <br\/>C\u00f4ng c\u1ee7a l\u1ef1c k\u00e9o l\u00e0: $A={{A}_{{{F}_{ms}}}}+{{A}_{P}}=384+675=1059J$ <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":2}]}],"id_ques":2712},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":5,"ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/vatly/bai14/lv2/img\/h13.jpg'\/><\/center>H\u1ec7 th\u1ed1ng r\u00f2ng r\u1ecdc nh\u01b0 h\u00ecnh v\u1ebd cho ta l\u1ee3i nh\u01b0 th\u1ebf n\u00e0o v\u1ec1 l\u1ef1c? ","select":["A. L\u1ee3i 2 l\u1ea7n.","B. L\u1ee3i 3 l\u1ea7n.","C. L\u1ee3i 4 l\u1ea7n.","D. L\u1ee3i 6 l\u1ea7n."],"hint":"","explain":"<span class='basic_left'>R\u00f2ng r\u1ecdc \u0111\u1ed9ng cho ta l\u1ee3i 2 l\u1ea7n v\u1ec1 l\u1ef1c, r\u00f2ng r\u1ecdc c\u1ed1 \u0111\u1ecbnh kh\u00f4ng cho ta l\u1ee3i v\u1ec1 l\u1ef1c. V\u1eady 2 r\u00f2ng r\u1ecdc \u0111\u1ed9ng v\u00e0 m\u1ed9t r\u00f2ng r\u1ecdc c\u1ed1 \u0111\u1ecbnh cho ta l\u1ee3i $2 . 2 = 4$ l\u1ea7n v\u1ec1 l\u1ef1c.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":2}]}],"id_ques":2713},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":"D\u00f9ng h\u1ec7 th\u1ed1ng g\u1ed3m 3 r\u00f2ng r\u1ecdc \u0111\u1ed9ng v\u00e0 3 r\u00f2ng r\u1ecdc c\u1ed1 \u0111\u1ecbnh \u0111\u1ec3 k\u00e9o v\u1eadt l\u00ean th\u00ec cho ta l\u1ee3i bao nhi\u00eau l\u1ea7n v\u1ec1 l\u1ef1c ?","select":["A. L\u1ee3i 8 l\u1ea7n v\u1ec1 l\u1ef1c.","B. L\u1ee3i 4 l\u1ea7n v\u1ec1 l\u1ef1c.","C. L\u1ee3i 6 l\u1ea7n v\u1ec1 l\u1ef1c.","D. L\u1ee3i 2 l\u1ea7n v\u1ec1 l\u1ef1c."],"hint":"","explain":"<span class='basic_left'>R\u00f2ng r\u1ecdc \u0111\u1ed9ng cho ta l\u1ee3i 2 l\u1ea7n v\u1ec1 l\u1ef1c, r\u00f2ng r\u1ecdc c\u1ed1 \u0111\u1ecbnh kh\u00f4ng cho ta l\u1ee3i v\u1ec1 l\u1ef1c. V\u1eady 3 r\u00f2ng r\u1ecdc \u0111\u1ed9ng v\u00e0 3 r\u00f2ng r\u1ecdc c\u1ed1 \u0111\u1ecbnh cho ta l\u1ee3i $2 . 2 . 2 = 8$ l\u1ea7n v\u1ec1 l\u1ef1c.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span><\/span> ","column":2}]}],"id_ques":2714},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":"Ng\u01b0\u1eddi ta k\u00e9o v\u1eadt kh\u1ed1i l\u01b0\u1ee3ng 24kg l\u00ean m\u1ed9t m\u1eb7t ph\u1eb3ng nghi\u00eang d\u00e0i 15m v\u00e0 cao 1,8m. L\u1ef1c c\u1ea3n do ma s\u00e1t l\u00e0 $F_c = 36N$. Coi v\u1eadt chuy\u1ec3n \u0111\u1ed9ng \u0111\u1ec1u. C\u00f4ng c\u1ee7a ng\u01b0\u1eddi k\u00e9o c\u00f3 th\u1ec3 nh\u1eadn gi\u00e1 tr\u1ecb n\u00e0o sau \u0111\u00e2y? ","select":["A. $A = 972J$.","B. $A = 297J$.","C. $A = 792J$.","D. M\u1ed9t gi\u00e1 tr\u1ecb kh\u00e1c."],"hint":"","explain":"<span class='basic_left'>C\u00f4ng c\u1ee7a l\u1ef1c ma s\u00e1t: ${{A}_{{{F}_{ms}}}}=36\\times 15=540J$ <br\/>C\u00f4ng c\u1ee7a tr\u1ecdng l\u1ef1c l\u00e0: ${{A}_{P}}=24\\times 10\\times 1,8=432J$ <br\/>C\u00f4ng c\u1ee7a l\u1ef1c k\u00e9o l\u00e0: $A={{A}_{{{F}_{ms}}}}+{{A}_{P}}=540+432=972J$<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span><\/span> ","column":2}]}],"id_ques":2715},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[4]],"list":[{"point":5,"ques":"Ng\u01b0\u1eddi ta k\u00e9o v\u1eadt kh\u1ed1i l\u01b0\u1ee3ng 24kg l\u00ean m\u1ed9t m\u1eb7t ph\u1eb3ng nghi\u00eang d\u00e0i 15m v\u00e0 cao 1,8m. L\u1ef1c c\u1ea3n do ma s\u00e1t l\u00e0 36N. Coi v\u1eadt chuy\u1ec3n \u0111\u1ed9ng \u0111\u1ec1u. Hi\u1ec7u su\u1ea5t c\u1ee7a m\u1eb7t ph\u1eb3ng nghi\u00eang l\u00e0 bao nhi\u00eau?","select":["A. $H = 25,56 \\%$.","B. $H = 45,56 \\%$.","C. $H = 35,56 \\%$.","D. $H = 44,44 \\%$."],"hint":"","explain":"<span class='basic_left'>C\u00f4ng c\u1ee7a l\u1ef1c ma s\u00e1t: ${{A}_{{{F}_{ms}}}}=36\\times 15=540J$ <br\/>C\u00f4ng c\u1ee7a tr\u1ecdng l\u1ef1c l\u00e0: ${{A}_{P}}=24\\times 10\\times 1,8=432J$ <br\/>C\u00f4ng c\u1ee7a l\u1ef1c k\u00e9o l\u00e0: $A={{A}_{{{F}_{ms}}}}+{{A}_{P}}=540+432=972J$<br\/> Hi\u1ec7u su\u1ea5t c\u1ee7a m\u1eb7t ph\u1eb3ng nghi\u00eang l\u00e0: $H=\\dfrac{432}{972}=44,44\\%$ <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 D.<\/span><\/span> ","column":2}]}],"id_ques":2716},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":5,"ques":"M\u1ed9t thang m\u00e1y c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng $m = 580$kg, \u0111\u01b0\u1ee3c k\u00e9o t\u1eeb \u0111\u00e1y h\u1ea7m m\u1ecf s\u00e2u 125m l\u00ean m\u1eb7t \u0111\u1ea5t b\u1eb1ng l\u1ef1c c\u0103ng c\u1ee7a m\u1ed9t d\u00e2y c\u00e1p do m\u00e1y th\u1ef1c hi\u1ec7n. Bi\u1ebft hi\u1ec7u su\u1ea5t c\u1ee7a m\u00e1y l\u00e0 $75\\%$. C\u00f4ng nh\u1ecf nh\u1ea5t c\u1ee7a l\u1ef1c c\u0103ng th\u1ef1c hi\u1ec7n v\u00e0 c\u00f4ng do m\u00e1y th\u1ef1c hi\u1ec7n c\u00f3 th\u1ec3 nh\u1eadn gi\u00e1 tr\u1ecb n\u00e0o sau: ","select":["A. $- 725kJ$ v\u00e0 $966,67kJ$.","B. $725kJ$ v\u00e0 $- 966,7 kJ$.","C. $725kJ$ v\u00e0 $966,67kJ$.","D. $- 725kJ$ v\u00e0 $- 966,67kJ$"],"hint":"","explain":"<span class='basic_left'>C\u00f4ng nh\u1ecf nh\u1ea5t c\u1ee7a l\u1ef1c c\u0103ng th\u1ef1c hi\u1ec7n : ${{A}_{1}}=580\\times 10\\times 125=725000J=725kJ$<br\/>C\u00f4ng do m\u00e1y th\u1ef1c hi\u1ec7n: $A=\\dfrac{725}{75\\%}=966,6kJ$ <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":2}]}],"id_ques":2717},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":"Hai ng\u01b0\u1eddi c\u00f9ng k\u00e9o m\u1ed9t c\u00e1i th\u00f9ng n\u1eb7ng tr\u00ean m\u1eb7t s\u00e0n n\u1eb1m ngang b\u1eb1ng c\u00e1c l\u1ef1c $F_1 = 200N$ v\u00e0 $F_2 = 350N$ theo h\u01b0\u1edbng chuy\u1ec3n \u0111\u1ed9ng c\u1ee7a v\u1eadt. C\u00f4ng t\u1ed5ng c\u1ed9ng khi th\u00f9ng d\u1ecbch chuy\u1ec3n qu\u00e3ng \u0111\u01b0\u1eddng $S = 10m$ c\u1ee7a hai ng\u01b0\u1eddi l\u00e0 bao nhi\u00eau? ","select":["A. 5000J.","B. 5500J.","C. 6000J.","D. 6500J."],"hint":"","explain":"<span class='basic_left'>T\u1ed5ng c\u00f4ng khi th\u00f9ng d\u1ecbch chuy\u1ec3n qu\u00e3ng \u0111\u01b0\u1eddng $S = 10m$ l\u00e0: <br\/> $A={{A}_{1}}+{{A}_{2}}=200\\times 10+350\\times 10=5500J$. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":2}]}],"id_ques":2718},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":5,"ques":"Ng\u01b0\u1eddi ta d\u00f9ng m\u1ed9t m\u1eb7t ph\u1eb3ng nghi\u00eang \u0111\u1ec3 k\u00e9o m\u1ed9t v\u1eadt c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 50kg l\u00ean cao 2m. N\u1ebfu kh\u00f4ng c\u00f3 ma s\u00e1t th\u00ec l\u1ef1c k\u00e9o l\u00e0 125N. Chi\u1ec1u d\u00e0i m\u1eb7t ph\u1eb3ng nghi\u00eang l\u00e0:","select":["A. 6m.","B. 7m.","C. 8m.","D. 9m."],"hint":"","explain":"<span class='basic_left'>C\u00f4ng c\u1ee7a tr\u1ecdng l\u1ef1c s\u1ebd b\u1eb1ng v\u1edbi c\u00f4ng c\u1ee7a l\u1ef1c k\u00e9o: <br\/>$A=P\\times h={{F}_{k}}\\times S$<br\/>Chi\u1ec1u d\u00e0i m\u1eb7t ph\u1eb3ng nghi\u00eang l\u00e0:<br\/>$S=\\dfrac{P\\times h}{{{F}_{k}}}$<br\/>Thay s\u1ed1: $S=\\dfrac{50\\times 10\\times 2}{125}=8m$ <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":2}]}],"id_ques":2719}],"lesson":{"save":0,"level":2}}