{"segment":[{"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":"Hai b\u1ea1n Long v\u00e0 Nam thi k\u00e9o n\u01b0\u1edbc t\u1eeb m\u1ed9t gi\u1ebfng l\u00ean. Long k\u00e9o g\u1ea7u n\u01b0\u1edbc n\u1eb7ng g\u1ea5p \u0111\u00f4i g\u1ea7u n\u01b0\u1edbc c\u1ee7a Nam. Th\u1eddi gian k\u00e9o g\u1ea7u n\u01b0\u1edbc l\u00ean c\u1ee7a nam l\u1ea1i ch\u1ec9 b\u1eb1ng m\u1ed9t n\u1eeda th\u1eddi gian c\u1ee7a Long. So s\u00e1nh c\u00f4ng su\u1ea5t trung b\u00ecnh c\u1ee7a Long v\u00e0 Nam? ","select":["A. C\u00f4ng su\u1ea5t c\u1ee7a Long l\u1edbn h\u01a1n v\u00ec g\u1ea7u n\u01b0\u1edbc c\u1ee7a Long n\u1eb7ng g\u1ea5p \u0111\u00f4i.","B. C\u00f4ng su\u1ea5t c\u1ee7a Nam l\u1edbn h\u01a1n v\u00ec th\u1eddi gian k\u00e9o n\u01b0\u1edbc c\u1ee7a Nam ch\u1ec9 b\u1eb1ng m\u1ed9t n\u1eefa th\u1eddi gian k\u00e9o n\u01b0\u1edbc c\u1ee7a Long.","C. C\u00f4ng su\u1ea5t c\u1ee7a Nam v\u00e0 Long Nh\u01b0 nhau. ","D. Kh\u00f4ng th\u1ec3 so s\u00e1nh \u0111\u01b0\u1ee3c."],"hint":"","explain":"<span class='basic_left'>Theo C\u00f4ng th\u1ee9c t\u00ednh c\u00f4ng su\u1ea5t:<br\/>$P=\\dfrac{A}{t}=\\dfrac{F\\times s}{t}$ <br\/>Do Long k\u00e9o g\u1ea7u n\u01b0\u1edbc n\u1eb7ng g\u1ea5p \u0111\u00f4i g\u1ea7u n\u01b0\u1edbc c\u1ee7a Nam, n\u00ean l\u1ef1c c\u1ee7a Long s\u1ebd ph\u1ea3i g\u1ea5p \u0111\u00f4i l\u1ef1c c\u1ee7a Nam m\u00e0 th\u1eddi gian k\u00e9o g\u1ea7u n\u01b0\u1edbc l\u00ean c\u1ee7a Nam l\u1ea1i ch\u1ec9 b\u1eb1ng m\u1ed9t n\u1eefa th\u1eddi gian c\u1ee7a Long n\u00ean c\u00f4ng su\u1ea5t c\u1ee7a Nam v\u00e0 Long nh\u01b0 nhau. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":1}]}],"id_ques":2720},{"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":"T\u00ednh c\u00f4ng su\u1ea5t c\u1ee7a m\u1ed9t ng\u01b0\u1eddi \u0111i b\u1ed9, n\u1ebfu trong $2$ gi\u1edd ng\u01b0\u1eddi \u0111\u00f3 \u0111i \u0111\u01b0\u1ee3c $10000$ b\u01b0\u1edbc v\u00e0 m\u1ed7i b\u01b0\u1edbc c\u1ea7n m\u1ed9t c\u00f4ng l\u00e0 $40J$. ","select":["A. $1,39W$","B. $200W$","C. $22,5W$","D. $55,56W$"],"hint":"","explain":"<span class='basic_left'>C\u00f4ng su\u1ea5t c\u1ee7a m\u1ed9t ng\u01b0\u1eddi \u0111i b\u1ed9 l\u00e0:<br\/>$P=\\dfrac{A}{t}=\\dfrac{10000\\times 40}{2\\times 3600}=55,56W$ <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 D.<\/span><\/span> ","column":2}]}],"id_ques":2721},{"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":"T\u00ednh c\u00f4ng su\u1ea5t c\u1ee7a d\u00f2ng n\u01b0\u1edbc ch\u1ea3y qua \u0111\u1eadp ng\u0103n cao $25m$ xu\u1ed1ng d\u01b0\u1edbi, bi\u1ebft r\u1eb1ng l\u01b0u l\u01b0\u1ee3ng d\u00f2ng n\u01b0\u1edbc l\u00e0 $120{{m}^{3}} \/$ ph\u00fat, kh\u1ed1i l\u01b0\u1ee3ng ri\u00eang c\u1ee7a n\u01b0\u1edbc l\u00e0 $1000kg\/{{m}^{3}}$. ","select":["A. $5.{{10}^{5}}W$","B. $3.{{10}^{7}}W$","C. $5.{{10}^{7}}W$","D. $10.{{10}^{5}}W$"],"hint":"","explain":"<span class='basic_left'>Kh\u1ed1i l\u01b0\u1ee3ng n\u01b0\u1edbc ch\u1ea3y trong m\u1ed9t ph\u00fat:<br\/> $m = 120 \\times 1000 = 12 \\times {{10}^{4}} kg$<br\/>Suy ra<br\/>$P=10\\times m=12\\times {{10}^{5}}$<br\/>$A=P\\times h=12\\times {{10}^{5}}\\times 25=3\\times {{10}^{7}}W}$<br\/>C\u00f4ng su\u1ea5t: $P=\\dfrac{A}{t}=\\dfrac{3\\times {{10}^{7}}}{60}=5\\times {{10}^{5}}W$<br\/><span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span><\/span> ","column":2}]}],"id_ques":2722},{"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":"Tr\u00ean m\u1ed9t m\u00e1y k\u00e9o c\u00f3 ghi c\u00f4ng su\u1ea5t $10 CV$ (m\u00e3 l\u1ef1c). N\u1ebfu coi $1CV = 736 W$ th\u00ec \u0111i\u1ec1u ghi tr\u00ean m\u00e1y k\u00e9o c\u00f3 \u00fd ngh\u0129a g\u00ec?","select":["A. M\u00e1y k\u00e9o c\u00f3 th\u1ec3 th\u1ef1c hi\u1ec7n c\u00f4ng $7360J$ trong $1$ gi\u00e2y.","B. M\u00e1y k\u00e9o c\u00f3 th\u1ec3 th\u1ef1c hi\u1ec7n c\u00f4ng $7360W$ trong $1$ gi\u00e2y.","C. M\u00e1y k\u00e9o c\u00f3 th\u1ec3 th\u1ef1c hi\u1ec7n c\u00f4ng $7360kJ$ trong $1$ gi\u1edd.","D. M\u00e1y k\u00e9o c\u00f3 th\u1ec3 th\u1ef1c hi\u1ec7n c\u00f4ng $7360kW$ trong $1$ gi\u1edd."],"hint":"","explain":"<span class='basic_left'>C\u00f4ng m\u00e1y k\u00e9o th\u1ef1c hi\u1ec7n \u0111\u01b0\u1ee3c trong th\u1eddi gian $t$ l\u00e0: $A= P \\times t$<br\/> Trong \u0111\u00f3, P l\u00e0 c\u00f4ng su\u1ea5t (W); t l\u00e0 th\u1eddi gian (gi\u00e2y)<br\/>C\u00f4ng m\u00e1y k\u00e9o c\u00f3 th\u1ec3 th\u1ef1c hi\u1ec7n \u0111\u01b0\u1ee3c trong $1s$:<br\/>$A=10\\times 736\\times 1=7360J$<br\/>C\u00f4ng m\u00e1y k\u00e9o c\u00f3 th\u1ec3 th\u1ef1c hi\u1ec7n trong $1$ gi\u1edd l\u00e0:<br\/> $A=10\\times 736\\times 3600=26496000J=26496\\,kJ$<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span><\/span> ","column":1}]}],"id_ques":2723},{"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 con ng\u1ef1a k\u00e9o m\u1ed9t c\u00e1i xe v\u1edbi m\u1ed9t l\u1ef1c kh\u00f4ng \u0111\u1ed5i b\u1eb1ng $80N$ v\u00e0 \u0111i \u0111\u01b0\u1ee3c $4,5km$ trong n\u1eeda gi\u1edd. T\u00ednh c\u00f4ng su\u1ea5t trung b\u00ecnh c\u1ee7a con ng\u1ef1a.","select":["A. $160W$.","B. $100W$.","C. $200W$.","D. $220W$."],"hint":"","explain":"<span class='basic_left'>$F = 80N, s = 4,5km = 4500m$, $t = 30$ ph\u00fat $= 1800s$<br\/>C\u00f4ng c\u1ee7a ng\u1ef1a:<br\/>$A = F \\times s = 80 \\times 4500 = 360 000J$<br\/>C\u00f4ng su\u1ea5t trung b\u00ecnh c\u1ee7a ng\u1ef1a:<br\/>$P=\\dfrac{A}{t}=\\dfrac{360000}{1800}=200W$ <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":2}]}],"id_ques":2724},{"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 c\u1ea7n tr\u1ee5c n\u00e2ng m\u1ed9t v\u1eadt n\u1eb7ng $1500N$ l\u00ean \u0111\u1ed9 cao $2m$ trong th\u1eddi gian $5$ gi\u00e2y. C\u00f4ng su\u1ea5t c\u1ee7a c\u1ea7n tr\u1ee5c s\u1ea3n ra l\u00e0: ","select":["A. $1500W$.","B. $750W$.","C. $600W$.","D. $300W$."],"hint":"","explain":"<span class='basic_left'>$P=\\dfrac{A}{t}=\\dfrac{1500\\times 2}{5}=600W$<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":2}]}],"id_ques":2725},{"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 c\u1ea7n c\u1ea9u m\u1ed7i l\u1ea7n n\u00e2ng \u0111\u01b0\u1ee3c m\u1ed9t contenn\u01a1 $10$ t\u1ea5n l\u00ean cao $5m$ m\u1ea5t $20$ gi\u00e2y. T\u00ednh c\u00f4ng su\u1ea5t do c\u1ea7n c\u1ea9u s\u1ea3n ra.","select":["A. $24000W$.","B. $25000W$.","C. $2000W$.","D. $3200W$."],"hint":"","explain":"<span class='basic_left'>$m = 10$ t\u1ea5n $= 10 000$ kg, $h = 5m, t = 20s$<br\/>C\u00f4ng su\u1ea5t do c\u1ea7n c\u1ea9u sinh ra:<br\/>$P=\\dfrac{A}{t}=\\dfrac{10\\times 10000\\times 5}{20}=25000W$<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":2}]}],"id_ques":2726},{"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 c\u1ea7n c\u1ea9u m\u1ed7i l\u1ea7n n\u00e2ng \u0111\u01b0\u1ee3c m\u1ed9t contenn\u01a1 $10$ t\u1ea5n l\u00ean cao $5m$ m\u1ea5t $20$ gi\u00e2y. C\u1ea7n c\u1ea9u n\u00e0y ch\u1ea1y b\u1eb1ng \u0111i\u1ec7n, v\u1edbi hi\u1ec7u su\u1ea5t $65\\%$. H\u1ecfi, \u0111\u1ec3 b\u1ed1c x\u1ebfp $300$ contenn\u01a1 th\u00ec c\u1ea7n bao nhi\u00eau \u0111i\u1ec7n n\u0103ng?","select":["A. $200000000J$.","B. $300000000J$.","C. $150000000J$.","D. $230769230J$."],"hint":"","explain":"<span class='basic_left'>C\u00f4ng \u0111\u01b0a $300$ contenn\u01a1 l\u00ean cao $5m$ l\u00e0:<br\/>${{A}_{ci}}=300 \\times 10 \\times {{10}^{3}} \\times 10 \\times 5 = 15 \\times {{10}^{7}}J$<br\/>\u0110i\u1ec7n n\u0103ng c\u1ea7n ti\u00eau th\u1ee5:<br\/>$H=\\dfrac{{{A}_{ci}}}{{{A}_{tp}}}\\Times{{A}_{tp}}=\\dfrac{{{A}_{ci}}}{H}=\\dfrac{15\\times {{10}^{7}}}{0,65}=2307692330J$<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 D.<\/span><\/span> ","column":2}]}],"id_ques":2727},{"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":"C\u1ea7n c\u1ea9u th\u1ee9 nh\u1ea5t n\u00e2ng m\u1ed9t v\u1eadt n\u1eb7ng $4000N$ l\u00ean cao $2m$ trong $4$ gi\u00e2y. C\u1ea7n c\u1ea9u th\u1ee9 hai n\u00e2ng v\u1eadt n\u1eb7ng $2000N$ l\u00ean cao $4m$ trong v\u00f2ng $2$ gi\u00e2y. So s\u00e1nh c\u00f4ng su\u1ea5t c\u1ee7a 2 c\u1ea7n c\u1ea9u. ","select":["A. ${{\\wp }_{1}} > {{\\wp }_{2}}$","B. ${{\\wp }_{1}} = {{\\wp }_{2}}$","C. ${{\\wp }_{1}} < {{\\wp }_{2}}$","D. Kh\u00f4ng \u0111\u1ee7 d\u1eef ki\u1ec7n so s\u00e1nh."],"hint":"","explain":"<span class='basic_left'>${{\\wp }_{1}}=\\dfrac{4000\\times 2}{4}=2000W$<br\/>${{\\wp }_{2}}=\\dfrac{2000\\times 4}{2}=4000W$<br\/> $\\Rightarrow {{\\wp }_{1}} < {{\\wp }_{2}}$ <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":2}]}],"id_ques":2728},{"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 t\u00f2a nh\u00e0 cao $10$ t\u1ea7ng, m\u1ed7i t\u1ea7ng cao $3,4m$, c\u00f3 m\u1ed9t thang ch\u1edf t\u1ed1i \u0111a \u0111\u01b0\u1ee3c $20$ ng\u01b0\u1eddi, m\u1ed7i ng\u01b0\u1eddi c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng trung b\u00ecnh $50kg$. M\u1ed7i chuy\u1ec3n l\u00ean t\u1ea7ng $10$, n\u1ebfu kh\u00f4ng d\u1eebng \u1edf c\u00e1c t\u1ea7ng kh\u00e1c, m\u1ea5t m\u1ed9t ph\u00fat. C\u00f4ng su\u1ea5t t\u1ed1i thi\u1ec3u c\u1ee7a \u0111\u1ed9ng c\u01a1 thang m\u00e1y ph\u1ea3i l\u00e0 bao nhi\u00eau ?","select":["A. $5,1 MW$.","B. $5,1kW$.","C. $100 kW$.","D. $20 W$."],"hint":"","explain":"<span class='basic_left'> \u0110\u1ec3 l\u00ean \u0111\u1ebfn t\u1ea7ng $10$, thang m\u00e1y ph\u1ea3i v\u01b0\u1ee3t qua $9$ t\u1ea7ng, v\u1eady ph\u1ea3i l\u00ean cao: $h = 3,4 \\times 9 = 30,6m$<br\/>Kh\u1ed1i l\u01b0\u1ee3ng c\u1ee7a $20$ ng\u01b0\u1eddi l\u00e0 $m = 50 \\times 20 = 1000 kg$<br\/>Tr\u1ecdng l\u01b0\u1ee3ng c\u1ee7a $20$ ng\u01b0\u1eddi l\u00e0: $P = 10000N$<br\/>V\u1eady c\u00f4ng ph\u1ea3i ti\u00eau t\u1ed1n cho m\u1ed7i l\u1ea7n thang l\u00ean t\u1ed1i thi\u1ec3u l\u00e0:<br\/>$A = P \\times h = 10000 \\times 30,6 = 306 000 J$<br\/>C\u00f4ng su\u1ea5t t\u1ed1i thi\u1ec3u c\u1ee7a \u0111\u1ed9ng c\u01a1 k\u00e9o thang l\u00ean l\u00e0:<br\/>$\\wp =\\dfrac{A}{t}=\\dfrac{306000}{60}=5100W=5,1kW$ <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":2}]}],"id_ques":2729},{"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":"\u0110\u01a1n v\u1ecb c\u1ee7a c\u00f4ng su\u1ea5t l\u00e0:","select":["A. Jun.","B. W.","C. J.s.","D. T\u1ea5t c\u1ea3 c\u00e1c \u0111\u00e1p \u00e1n tr\u00ean."],"hint":"","explain":"<span class='basic_left'>\u0110\u01a1n v\u1ecb c\u1ee7a c\u00f4ng su\u1ea5t l\u00e0 W. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":2}]}],"id_ques":2730},{"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 c\u00e0y m\u1ed9t m\u1ea3nh ru\u1ed9ng, n\u1ebfu d\u00f9ng tr\u00e2u th\u00ec m\u1ea5t $3$ gi\u1edd, c\u00f2n n\u1ebfu d\u00f9ng m\u00e1y th\u00ec m\u1ea5t $20$ ph\u00fat. H\u1ecfi c\u00f4ng su\u1ea5t c\u1ee7a m\u00e1y g\u1ea5p bao nhi\u00eau l\u1ea7n c\u00f4ng su\u1ea5t c\u1ee7a tr\u00e2u?","select":["A. B\u1eb1ng nhau.","B. G\u1ea5n $2$ l\u1ea7n.","C. G\u1ea5p $0,5$ l\u1ea7n.","D. G\u1ea5p $9$ l\u1ea7n."],"hint":"","explain":"<span class='basic_left'>20 ph\u00fat = $\\dfrac{1}{3}h$<br\/>Khi c\u00e0y ho\u1eb7c khi d\u00f9ng tr\u00e2u th\u00ec c\u00f4ng \u0111\u1ec3 c\u00e0y \u0111\u1ec1u kh\u00f4ng \u0111\u1ed5i.<br\/>N\u00ean c\u00f4ng su\u1ea5t c\u1ee7a m\u00e1y g\u1ea5p c\u00f4ng su\u1ea5t c\u1ee7a tr\u00e2u l\u00e0: $\\dfrac{3}{\\left(\\dfrac{1}{3}\\right)}=9$<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 D.<\/span><\/span> ","column":2}]}],"id_ques":2731},{"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":"C\u00f4ng su\u1ea5t trung b\u00ecnh c\u1ee7a m\u1ed9t ng\u01b0\u1eddi \u0111i b\u1ed9 l\u00e0 $300W$. N\u1ebfu trong $2,5$ gi\u1edd ng\u01b0\u1eddi \u0111\u00f3 \u0111i \u0111\u01b0\u1ee3c $10000$ b\u01b0\u1edbc, th\u00ec m\u1ed7i b\u01b0\u1edbc ch\u00e2n c\u1ea7n m\u1ed9t c\u00f4ng l\u00e0:","select":["A. $270 J$.","B. $270kJ$.","C. $0,075 J$.","D. $75 J$."],"hint":"","explain":"<span class='basic_left'>C\u00f4ng trong $2,5$ gi\u1edd l\u00e0: $300 \\times 2,5 \\times 3600= 2700000 J$<br\/>C\u00f4ng m\u1ed7i b\u01b0\u1edbc ch\u00e2n l\u00e0: $\\dfrac{2700000}{10000}=270J$ <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span><\/span> ","column":2}]}],"id_ques":2732},{"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":"\u0110i\u1ec1u n\u00e0o sau \u0111\u00e2y \u0111\u00fang khi n\u00f3i v\u1ec1 c\u00f4ng su\u1ea5t? ","select":["A. C\u00f4ng su\u1ea5t \u0111\u01b0\u1ee3c x\u00e1c \u0111\u1ecbnh b\u1eb1ng c\u00f4ng th\u1ef1c hi\u1ec7n \u0111\u01b0\u1ee3c trong m\u1ed9t \u0111\u01a1n v\u1ecb th\u1eddi gian.","B. C\u00f4ng su\u1ea5t \u0111\u01b0\u1ee3c x\u00e1c \u0111\u1ecbnh b\u1eb1ng l\u1ef1c t\u00e1c d\u1ee5ng trong $1$ gi\u00e2y.","C. C\u00f4ng su\u1ea5t \u0111\u01b0\u1ee3c x\u00e1c \u0111\u1ecbnh b\u1eb1ng c\u00f4ng th\u1ee9c $P = A \\times t$.","D. C\u00f4ng su\u1ea5t \u0111\u01b0\u1ee3c x\u00e1c \u0111\u1ecbnh b\u1eb1ng c\u00f4ng th\u1ef1c hi\u1ec7n khi v\u1eadt d\u1ecbch chuy\u1ec3n \u0111\u01b0\u1ee3c $1$ m\u00e9t."],"hint":"","explain":"<span class='basic_left'>C\u00f4ng su\u1ea5t \u0111\u01b0\u1ee3c x\u00e1c \u0111\u1ecbnh b\u1eb1ng c\u00f4ng th\u1ef1c hi\u1ec7n \u0111\u01b0\u1ee3c trong m\u1ed9t \u0111\u01a1n v\u1ecb th\u1eddi gian. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span><\/span> ","column":1}]}],"id_ques":2733},{"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":"L\u00e0m th\u1ebf n\u00e0o bi\u1ebft ai l\u00e0m vi\u1ec7c kh\u1ecfe h\u01a1n? H\u00e3y ch\u1ecdn ph\u01b0\u01a1ng \u00e1n \u0111\u00fang? ","select":["A. So s\u00e1nh c\u00f4ng th\u1ef1c hi\u1ec7n c\u1ee7a hai ng\u01b0\u1eddi, ai th\u1ef1c hi\u1ec7n c\u00f4ng l\u1edbn h\u01a1n th\u00ec ng\u01b0\u1eddi \u0111\u00f3 l\u00e0m vi\u1ec7c kh\u1ecfe h\u01a1n.","B. So s\u00e1nh th\u1eddi gian l\u00e0m vi\u1ec7c, ai l\u00e0m vi\u1ec7c \u00edt th\u1eddi gian h\u01a1n th\u00ec ng\u01b0\u1eddi \u0111\u00f3 kh\u1ecfe h\u01a1n.","C. So s\u00e1nh c\u00f4ng th\u1ef1c hi\u1ec7n trong c\u00f9ng m\u1ed9t th\u1eddi gian ai th\u1ef1c hi\u1ec7n c\u00f4ng l\u1edbn h\u01a1n th\u00ec ng\u01b0\u1eddi \u0111\u00f3 l\u00e0m vi\u1ec7c kh\u1ecfe h\u01a1n.","D. C\u00e1c ph\u01b0\u01a1ng \u00e1n tr\u00ean \u0111\u1ec1u kh\u00f4ng ch\u1ecdn \u0111\u01b0\u1ee3c."],"hint":"","explain":"<span class='basic_left'>\u0110\u1ec3 bi\u1ebft ai l\u00e0m vi\u1ec7c kh\u1ecfe h\u01a1n ta so s\u00e1nh c\u00f4ng th\u1ef1c hi\u1ec7n trong c\u00f9ng m\u1ed9t th\u1eddi gian ai th\u1ef1c hi\u1ec7n c\u00f4ng l\u1edbn h\u01a1n th\u00ec ng\u01b0\u1eddi \u0111\u00f3 l\u00e0m vi\u1ec7c kh\u1ecfe h\u01a1n. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":1}]}],"id_ques":2734},{"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":"\u0110\u1ec3 k\u00e9o v\u1eadt c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng $72kg$ l\u00ean cao $10m$ ng\u01b0\u1eddi ta d\u00f9ng m\u00e1y t\u1eddi c\u00f3 c\u00f4ng su\u1ea5t $1580 W$ v\u00e0 hi\u1ec7u su\u1ea5t $75\\%$.Th\u1eddi gian m\u00e1y th\u1ef1c hi\u1ec7n c\u00f4ng vi\u1ec7c tr\u00ean c\u00f3 th\u1ec3 nh\u1eadn gi\u00e1 tr\u1ecb n\u00e0o sau: ","select":["A. $6,075$ gi\u00e2y.","B. $607,5$ gi\u00e2y.","C. $60,75$ gi\u00e2y.","D. $6075$ gi\u00e2y."],"hint":"","explain":"<span class='basic_left'>C\u00f4ng c\u1ea7n \u0111\u1ec3 n\u00e2ng v\u1eadt l\u00ean l\u00e0: $A = m \\times g \\times h=72 \\times 10 \\times 10 = 7200J$<br\/>Th\u1eddi gian l\u00e0 : $t=\\dfrac{A}{P\\times H}=\\dfrac{7200}{1580\\times 75\\%}=6,075s$<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span><\/span> ","column":2}]}],"id_ques":2735},{"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 m\u00e1y b\u01a1m ch\u1ea1y b\u1eb1ng \u0111\u1ed9ng c\u01a1 \u0111i\u1ec7n ti\u00eau th\u1ee5 c\u00f4ng su\u1ea5t $7,5 kW$. Trong $1$ gi\u00e2y m\u00e1y h\u00fat $60$ l\u00edt n\u01b0\u1edbc l\u00ean cao $6,5m$. Hi\u1ec7u su\u1ea5t c\u1ee7a m\u00e1y b\u01a1m l\u00e0 bao nhi\u00eau?","select":["A. $H = 50\\%$.","B. $H = 54\\%$.","C. $H = 52\\%$.","D. M\u1ed9t gi\u00e1 tr\u1ecb kh\u00e1c."],"hint":"","explain":"<span class='basic_left'>C\u00f4ng m\u00e1y b\u01a1m th\u1ef1c hi\u1ec7n \u0111\u01b0\u1ee3c :<br\/>${{A}_{ci}}=P\\times h=60\\times 10\\times 6,5=3900J$ <br\/>C\u00f4ng m\u00e1y b\u01a1m ti\u00eau th\u1ee5:<br\/>${{A}_{tp}}=P\\times t=7,5kW\\times 1s=7500J$ <br\/>Hi\u1ec7u su\u1ea5t l\u00e0:<br\/>$H=\\dfrac{{{A}_{ci}}}{{{A}_{tp}}}=\\dfrac{3900}{7500}=0,52=52\\%$ <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":2}]}],"id_ques":2736},{"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 m\u00e1y b\u01a1m b\u01a1m n\u01b0\u1edbc l\u00ean cao $5,5m$. Trong m\u1ed7i gi\u00e2y m\u00e1y sinh c\u00f4ng $7500J$. H\u1ecfi m\u00e1y ho\u1ea1t \u0111\u1ed9ng li\u00ean t\u1ee5c trong $1$ gi\u1edd, th\u1ec3 t\u00edch n\u01b0\u1edbc m\u00e0 m\u00e1y b\u01a1m chuy\u1ec3n \u0111\u01b0\u1ee3c l\u00ean cao l\u00e0 bao nhi\u00eau? ","select":["A. $V = 49,9c{{m}^{3}}$.","B. $V = 4900,9c{{m}^{3}}$.","C. $V = 490,9{{m}^{3}}$.","D. $V = 49000,9{{m}^{3}}$."],"hint":"","explain":"<span class='basic_left'>C\u00f4ng m\u00e1y b\u01a1m sinh ra trong $1$ gi\u1edd: $A=7500\\times 3600=27\\times {{10}^{6}}J$ <br\/>Th\u1ec3 t\u00edch n\u01b0\u1edbc l\u00e0: $V=\\dfrac{27\\times {{10}^{6}}}{5,5\\times 10}=490909l=490{{m}^{3}}$<br\/><br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":2}]}],"id_ques":2737},{"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\u00f4t m\u00e1y bay tr\u1ef1c th\u0103ng khi c\u1ea5t c\u00e1nh, \u0111\u1ed9ng c\u01a1 t\u1ea1o ra m\u1ed9t l\u1ef1c ph\u00e1t \u0111\u1ed9ng $10500N$, sau $90$ gi\u00e2y m\u00e1y bay \u0111\u1ea1t \u0111\u1ed9 cao $850m$. C\u00f4ng su\u1ea5t c\u1ee7a \u0111\u1ed9ng c\u01a1 m\u00e1y bay c\u00f3 th\u1ec3 nh\u1eadn gi\u00e1 tr\u1ecb n\u00e0o sau:","select":["A. $P = 9916,67 W$.","B. $P = 991666,67 W$.","C. $P = 99166,67 W$.","D. M\u1ed9t gi\u00e1 tr\u1ecb kh\u00e1c."],"hint":"","explain":"<span class='basic_left'>$P=\\dfrac{10500\\times 850}{90}=99116W$ <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":2}]}],"id_ques":2738},{"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 th\u00e1c n\u01b0\u1edbc cao $120m$ c\u00f3 l\u01b0u l\u01b0\u1ee3ng $50{{m}^{3}}\/s$, kh\u1ed1i l\u01b0\u1ee3ng ri\u00eang c\u1ee7a n\u01b0\u1edbc l\u00e0 $1000kg\/{{m}^{3}}$. T\u00ednh c\u00f4ng su\u1ea5t c\u1ef1c \u0111\u1ea1i m\u00e0 ta c\u00f3 th\u1ec3 khai th\u00e1c \u0111\u01b0\u1ee3c c\u1ee7a th\u00e1c n\u01b0\u1edbc. Gi\u1ea3 s\u1eed m\u1ed9t m\u00e1y ph\u00e1t \u0111i\u1ec7n s\u1eed d\u1ee5ng \u0111\u01b0\u1ee3c $20\\%$ c\u00f4ng su\u1ea5t c\u1ee7a th\u00e1c n\u01b0\u1edbc, th\u00ec c\u00f9ng l\u00fac m\u00e1y ph\u00e1t \u0111i\u1ec7n c\u00f3 th\u1ec3 th\u1eafp s\u00e1ng b\u00ecnh th\u01b0\u1eddng t\u1ed1i \u0111a bao nhi\u00eau b\u00f3ng \u0111\u00e8n \u0111i\u1ec7n $60W$? ","select":["A. ${{P}_{max }} = 6.{{10}^{7}} W; N= 10000$ \u0111\u00e8n.","B. ${{P}_{max }} = 12.{{10}^{5}} W; N= 200000$ \u0111\u00e8n.","C. ${{P}_{max }} = 6.{{10}^{7}} W; N= 200$ \u0111\u00e8n.","D. ${{P}_{max }} = 6.{{10}^{7}} W; N= 200000$ \u0111\u00e8n."],"hint":"","explain":"<span class='basic_left'>Kh\u1ed1i l\u01b0\u1ee3ng n\u01b0\u1edbc \u0111\u1ed5 xu\u1ed1ng th\u00e1c trong $1s$ l\u00e0:<br\/>$m = D \\times L = 1000 x 50= 50000kg$<br\/>C\u00f4ng su\u1ea5t c\u1ef1c \u0111\u1ea1i m\u00e0 ta c\u00f3 th\u1ec3 khai th\u00e1c \u0111\u01b0\u1ee3c c\u1ee7a th\u00e1c n\u01b0\u1edbc l\u00e0:<br\/>${{P}_{max }} = 10m \\times h = 10 \\times 50000 \\times 120 = 6 \\times {{10}^{7}} W$<br\/> S\u1ed1 b\u00f3ng \u0111\u00e8n \u0111i\u1ec7n $60W$ t\u1ed1i \u0111a c\u00f3 th\u1ec3 th\u1eafp s\u00e1ng b\u00ecnh th\u01b0\u1eddng:<br\/> $N=\\dfrac{{{P}_{ich}}}{{{P}_{d}}}=\\dfrac{1,2\\times {{10}^{7}}}{60}=200000$ <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 D.<\/span><\/span> ","column":2}]}],"id_ques":2739}],"lesson":{"save":0,"level":2}}