{"segment":[{"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":"L\u1ef1c \u0111\u1ea9y \u00c1c-si-m\u00e9t ph\u1ee5 thu\u1ed9c v\u00e0o? ","select":["A. Tr\u1ecdng l\u01b0\u1ee3ng ri\u00eang c\u1ee7a ch\u1ea5t l\u1ecfng v\u00e0 c\u1ee7a v\u1eadt.","B. Tr\u1ecdng l\u01b0\u1ee3ng ri\u00eang c\u1ee7a ch\u1ea5t l\u1ecfng v\u00e0 th\u1ec3 t\u00edch c\u1ee7a ph\u1ea7n ch\u1ea5t l\u1ecfng b\u1ecb v\u1eadt chi\u1ebfm ch\u1ed7.","C. Tr\u1ecdng l\u01b0\u1ee3ng ri\u00eang v\u00e0 c\u1ee7a v\u1eadt.","D. Tr\u1ecdng l\u01b0\u1ee3ng c\u1ee7a v\u1eadt v\u00e0 th\u1ec3 t\u00edch c\u1ee7a ph\u1ea7n ch\u1ea5t l\u1ecfng b\u1ecb v\u1eadt chi\u1ebfm ch\u1ed7."],"hint":"","explain":"<span class='basic_left'>L\u1ef1c \u0111\u1ea9y \u00c1c-si-m\u00e9t ph\u1ee5 thu\u1ed9c v\u00e0o tr\u1ecdng l\u01b0\u1ee3ng ri\u00eang c\u1ee7a ch\u1ea5t l\u1ecfng v\u00e0 th\u1ec3 t\u00edch c\u1ee7a ph\u1ea7n ch\u1ea5t l\u1ecfng b\u1ecb v\u1eadt chi\u1ebfm ch\u1ed7.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":1}]}],"id_ques":2640},{"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":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/vatly/bai10/lv2/img\/h2.jpg'\/><\/center>Ba qu\u1ea3 c\u1ea7u b\u1eb1ng th\u00e9p nh\u00fang trong n\u01b0\u1edbc (h\u00ecnh tr\u00ean).L\u1ef1c \u00c1c-si-m\u00e9t t\u00e1c d\u1ee5ng l\u00ean qu\u1ea3 c\u1ea7u n\u00e0o l\u1edbn nh\u1ea5t? ","select":["A. Qu\u1ea3 3, v\u00ec n\u00f3 \u1edf s\u00e2u nh\u1ea5t.","B. Qu\u1ea3 2, v\u00ec n\u00f3 l\u1edbn nh\u1ea5t.","C. Qu\u1ea3 1, v\u00ec n\u00f3 nh\u1ecf nh\u1ea5t.","D. B\u1eb1ng nhau v\u00ec \u0111\u1ec1u b\u1eb1ng th\u00e9p v\u00e0 \u0111\u1ec1u nh\u00fang trong n\u01b0\u1edbc."],"hint":"","explain":"<span class='basic_left'>L\u1ef1c \u0111\u1ea9y \u00c1c-si-m\u00e9t ph\u1ee5 thu\u1ed9c v\u00e0o tr\u1ecdng l\u01b0\u1ee3ng ri\u00eang c\u1ee7a ch\u1ea5t l\u1ecfng v\u00e0 th\u1ec3 t\u00edch c\u1ee7a ph\u1ea7n ch\u1ea5t l\u1ecfng b\u1ecb v\u1eadt chi\u1ebfm ch\u1ed7, n\u00ean l\u1ef1c \u00c1c-si-m\u00e9t t\u00e1c d\u1ee5ng l\u00ean qu\u1ea3 c\u1ea7u 2 l\u1edbn nh\u1ea5t do qu\u1ea3 c\u1ea7u 2 to nh\u1ea5t.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":1}]}],"id_ques":2641},{"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":"Th\u1ec3 t\u00edch c\u1ee7a m\u1ed9t mi\u1ebfng s\u1eaft l\u00e0 ${2d{m}^{3}}$. L\u1ef1c \u0111\u1ea9y t\u00e1c d\u1ee5ng l\u00ean mi\u1ebfng s\u1eaft khi nh\u00fang ch\u00ecm trong n\u01b0\u1edbc s\u1ebd nh\u1eadn gi\u00e1 tr\u1ecb n\u00e0o trong c\u00e1c gi\u00e1 tr\u1ecb sau:","select":["A. F = 15N.","B. F = 20N.","C. F = 25N.","D. F = 10N."],"hint":"","explain":"<span class='basic_left'>Ta c\u00f3: 2${d{m}^{3}}$ = 0,002${{m}^{3}}$<br\/> L\u1ef1c \u0111\u1ea9y \u00c1c-si-m\u00e9t t\u00e1c d\u1ee5ng l\u00ean mi\u1ebfng s\u1eaft khi mi\u1ebfng s\u1eaft \u0111\u01b0\u1ee3c nh\u00fang ch\u00ecm trong n\u01b0\u1edbc l\u00e0: <br\/>$F_A$ = $V_s$x${{d}_{nc}}$ = $10000\\times 0,002=20N$<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":2}]}],"id_ques":2642},{"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 th\u1ecfi nh\u00f4m v\u00e0 m\u1ed9t th\u1ecfi \u0111\u1ed3ng c\u00f3 tr\u1ecdng l\u01b0\u1ee3ng nh\u01b0 nhau. Treo c\u00e1c th\u1ecfi nh\u00f4m v\u00e0 \u0111\u1ed3ng v\u00e0o hai ph\u00eda c\u1ee7a m\u1ed9t c\u00e2n treo. \u0110\u1ec3 c\u00e2n th\u0103ng b\u1eb1ng r\u1ed3i nh\u00fang ng\u1eadp c\u1ea3 hai th\u1ecfi \u0111\u1ed3ng th\u1eddi v\u00e0o hai b\u00ecnh \u0111\u1ef1ng n\u01b0\u1edbc. C\u00e2n b\u00e2y gi\u1edd c\u00f2n th\u0103ng b\u1eb1ng n\u1eefa kh\u00f4ng? ","select":["A. C\u00e2n th\u0103ng b\u1eb1ng.","B. Th\u1ecfi nh\u00f4m \u1edf th\u1ea5p h\u01a1n \u0111\u1ed3ng.","C. Th\u1ecfi nh\u00f4m \u1edf cao h\u01a1n \u0111\u1ed3ng.","D. M\u1ed9t \u0111\u00e1p \u00e1n kh\u00e1c."],"hint":"","explain":"<span class='basic_left'>L\u1ef1c \u0111\u1ea9y c\u1ee7a n\u01b0\u1edbc t\u00e1c d\u1ee5ng v\u00e0o hai th\u1ecfi t\u00ednh b\u1eb1ng c\u00f4ng th\u1ee9c: $F_1$ =$dV_1$; $F_2$ =d$V_2$ (trong \u0111\u00f3 d l\u00e0 tr\u1ecdng l\u01b0\u1ee3ng ri\u00eang c\u1ee7a n\u01b0\u1edbc, $V_1$ l\u00e0 th\u1ec3 t\u00edch c\u1ee7a th\u1ecfi nh\u00f4m, $V_2$ l\u00e0 th\u1ec3 t\u00edch c\u1ee7a th\u1ecfi \u0111\u1ed3ng)<br\/>V\u00ec tr\u1ecdng l\u01b0\u1ee3ng ri\u00eang c\u1ee7a \u0111\u1ed3ng l\u1edbn h\u01a1n c\u1ee7a nh\u00f4m n\u00ean $V_1$ > $V_2$, do \u0111\u00f3 $F_1$ > $F_2$.<br\/>V\u1eady c\u00e2n s\u1ebd kh\u00f4ng c\u00e2n b\u1eb1ng n\u1eefa khi nh\u00fang ng\u1eadp c\u1ea3 hai th\u1ecfi \u0111\u1ed3ng th\u1eddi v\u00e0o hai b\u00ecnh \u0111\u1ef1ng n\u01b0\u1edbc.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":2}]}],"id_ques":2643},{"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\u00f4ng th\u1ee9c t\u00ednh l\u1ef1c \u0111\u1ea9y \u00c1c-si-m\u00e9t: F = d.V. C\u00e1c \u0111\u1ea1i l\u01b0\u1ee3ng d v\u00e0 V l\u00e0 g\u00ec?","select":["A. d l\u00e0 tr\u1ecdng l\u01b0\u1ee3ng ri\u00eang c\u1ee7a v\u1eadt, V l\u00e0 th\u1ec3 t\u00edch c\u1ee7a v\u1eadt.","B. d l\u00e0 tr\u1ecdng l\u01b0\u1ee3ng ri\u00eang c\u1ee7a ch\u1ea5t l\u1ecfng, V l\u00e0 th\u1ec3 t\u00edch c\u1ee7a v\u1eadt.","C. d l\u00e0 tr\u1ecdng l\u01b0\u1ee3ng ri\u00eang c\u1ee7a ch\u1ea5t l\u1ecfng, V l\u00e0 th\u1ec3 t\u00edch c\u1ee7a ph\u1ea7n ch\u1ea5t l\u1ecfng b\u1ecb v\u1eadt chi\u1ebfm ch\u1ed7.","D. M\u1ed9t c\u00e2u tr\u1ea3 l\u1eddi kh\u00e1c."],"hint":"","explain":"<span class='basic_left'>$F_A$ = d . V, trong \u0111\u00f3: $F_A$ L\u1ef1c \u0111\u1ea9y Acsim\u00e9t (N). d: Tr\u1ecdng l\u01b0\u1ee3ng ri\u00eang c\u1ee7a ch\u1ea5t l\u1ecfng (N\/${{m}^{3}}$ )<br\/> V: Th\u1ec3 t\u00edch ch\u1ea5t l\u1ecfng b\u1ecb v\u1eadt chi\u1ebfm ch\u1ed7 (${{m}^{3}}$)<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":1}]}],"id_ques":2644},{"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":"Ba v\u1eadt l\u00e0m b\u1eb1ng ba ch\u1ea5t kh\u00e1c nhau l\u00e0 \u0111\u1ed3ng, s\u1eaft, nh\u00f4m, c\u00f3 l\u01b0\u1ee3ng b\u1eb1ng nhau. Khi nh\u00fang ch\u00fang ng\u1eadp v\u00e0o trong n\u01b0\u1edbc th\u00ec l\u1ef1c \u0111\u1ea9y n\u01b0\u1edbc t\u00e1c d\u1ee5ng v\u00e0o v\u1eadt n\u00e0o l\u00e0 l\u1edbn nh\u1ea5t ?","select":["A. L\u1ef1c \u0111\u1ea9y c\u1ee7a n\u01b0\u1edbc t\u00e1c d\u1ee5ng v\u00e0o v\u1eadt b\u1eb1ng nh\u00f4m l\u1edbn nh\u1ea5t.","B. L\u1ef1c \u0111\u1ea9y c\u1ee7a n\u01b0\u1edbc t\u00e1c d\u1ee5ng v\u00e0o v\u1eadt b\u1eb1ng \u0111\u1ed3ng l\u1edbn nh\u1ea5t.","C. L\u1ef1c \u0111\u1ea9y c\u1ee7a n\u01b0\u1edbc t\u00e1c d\u1ee5ng v\u00e0o v\u1eadt b\u1eb1ng s\u1eaft l\u1edbn nh\u1ea5t.","D. T\u1ea5t c\u1ea3 \u0111\u1ec1u sai."],"hint":"","explain":"<span class='basic_left'>Ba v\u1eadt l\u00e0m b\u1eb1ng 3 ch\u1ea5t kh\u00e1c nhau n\u00ean kh\u1ed1i l\u01b0\u1ee3ng ri\u00eang c\u1ee7a ch\u00fang kh\u00e1c nhau. <br\/>V\u00ec kh\u1ed1i l\u01b0\u1ee3ng \u0111\u1ed3ng = kh\u1ed1i l\u01b0\u1ee3ng s\u1eaft = kh\u1ed1i l\u01b0\u1ee3ng nh\u00f4m => V\u0111\u1ed3ng < Vs\u1eaft < Vnh\u00f4m. Do \u0111\u00f3 l\u1ef1c \u0111\u1ea9y c\u1ee7a n\u01b0\u1edbc t\u00e1c d\u1ee5ng v\u00e0o v\u1eadt b\u1eb1ng nh\u00f4m l\u00e0 l\u1edbn nh\u1ea5t ,l\u1ef1c \u0111\u1ea9y c\u1ee7a n\u01b0\u1edbc t\u00e1c d\u1ee5ng v\u00e0o v\u1eadt b\u1eb1ng \u0111\u1ed3ng l\u00e0 b\u00e9 nh\u1ea5t.<br\/><br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span><\/span> ","column":1}]}],"id_ques":2645},{"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":"Ba v\u1eadt l\u00e0m b\u1eb1ng ba ch\u1ea5t kh\u00e1c nhau l\u00e0 s\u1eaft, nh\u00f4m, s\u1ee9, c\u00f3 h\u00ecnh kh\u00e1c nhau nh\u01b0ng th\u1ec3 t\u00edch b\u1eb1ng nhau. Khi nh\u00fang ch\u00fang ng\u1eadp v\u00e0o trong th\u00ec l\u1ef1c \u0111\u1ea9y n\u01b0\u1edbc t\u00e1c d\u1ee5ng v\u00e0o 3 v\u1eadt nh\u01b0 th\u1ebf n\u00e0o?","select":["A. L\u1ef1c \u0111\u1ea9y c\u1ee7a n\u01b0\u1edbc t\u00e1c d\u1ee5ng v\u00e0o v\u1eadt b\u1eb1ng nh\u00f4m l\u1edbn nh\u1ea5t.","B. L\u1ef1c \u0111\u1ea9y c\u1ee7a n\u01b0\u1edbc t\u00e1c d\u1ee5ng v\u00e0o v\u1eadt b\u1eb1ng s\u1eaft nh\u1ecf nh\u1ea5t.","C. L\u1ef1c \u0111\u1ea9y c\u1ee7a n\u01b0\u1edbc t\u00e1c d\u1ee5ng v\u00e0o v\u1eadt b\u1eb1ng s\u1ee9 l\u1edbn nh\u1ea5t.","D. L\u1ef1c \u0111\u1ea9y t\u00e1c d\u1ee5ng v\u00e0o 3 v\u1eadt b\u1eb1ng nhau."],"hint":"","explain":"<span class='basic_left'>L\u1ef1c \u0111\u1ea9y t\u00e1c d\u1ee5ng v\u00e0o 3 v\u1eadt b\u1eb1ng nhau.<br\/>V\u00ec F = d x V m\u00e0 3 v\u1eadt c\u00f3 th\u1ec3 t\u00edch b\u1eb1ng nhau.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 D.<\/span><\/span> ","column":1}]}],"id_ques":2646},{"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":"Th\u1ea3 m\u1ed9t vi\u00ean bi s\u1eaft v\u00e0o m\u1ed9t c\u1ed1c n\u01b0\u1edbc. Vi\u00ean bi c\u00e0ng xu\u1ed1ng s\u00e2u th\u00ec: ","select":["A. L\u1ef1c \u0111\u1ea9y \u00c1c-si-m\u00e9t t\u00e1c d\u1ee5ng l\u00ean n\u00f3 c\u00e0ng t\u0103ng, \u00e1p su\u1ea5t n\u01b0\u1edbc t\u00e1c d\u1ee5ng l\u00ean n\u00f3 c\u00e0ng t\u0103ng.","B. L\u1ef1c \u0111\u1ea9y \u00c1c-si-m\u00e9t t\u00e1c d\u1ee5ng l\u00ean n\u00f3 c\u00e0ng gi\u1ea3m, \u00e1p su\u1ea5t n\u01b0\u1edbc t\u00e1c d\u1ee5ng l\u00ean n\u00f3 c\u00e0ng t\u0103ng.","C. L\u1ef1c \u0111\u1ea9y \u00c1c-si-m\u00e9t t\u00e1c d\u1ee5ng l\u00ean n\u00f3 kh\u00f4ng \u0111\u1ed5i, \u00e1p su\u1ea5t n\u01b0\u1edbc t\u00e1c d\u1ee5ng l\u00ean n\u00f3 c\u00e0ng t\u0103ng.","D. L\u1ef1c \u0111\u1ea9y \u00c1c-si-m\u00e9t t\u00e1c d\u1ee5ng l\u00ean n\u00f3 kh\u00f4ng \u0111\u1ed5i, \u00e1p su\u1ea5t n\u01b0\u1edbc t\u00e1c d\u1ee5ng l\u00ean n\u00f3 kh\u00f4ng \u0111\u1ed5i."],"hint":"","explain":"<span class='basic_left'>Th\u1ea3 m\u1ed9t vi\u00ean bi s\u1eaft v\u00e0o m\u1ed9t c\u1ed1c n\u01b0\u1edbc. Vi\u00ean bi c\u00e0ng xu\u1ed1ng s\u00e2u th\u00ec l\u1ef1c \u0111\u1ea9y \u00c1c-si-m\u00e9t t\u00e1c d\u1ee5ng l\u00ean n\u00f3 kh\u00f4ng \u0111\u1ed5i, \u00e1p su\u1ea5t n\u01b0\u1edbc t\u00e1c d\u1ee5ng l\u00ean n\u00f3 c\u00e0ng t\u0103ng.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":1}]}],"id_ques":2647},{"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":"\u0110i\u1ec1u ki\u1ec7n \u0111\u1ec3 m\u1ed9t v\u1eadt \u0111\u1eb7c, kh\u00f4ng th\u1ea5m n\u01b0\u1edbc, ch\u1ec9 ch\u00ecm m\u1ed9t ph\u1ea7n trong n\u01b0\u1edbc l\u00e0: ","select":["A. Tr\u1ecdng l\u01b0\u1ee3ng ri\u00eang c\u1ee7a v\u1eadt b\u1eb1ng tr\u1ecdng l\u01b0\u1ee3ng ri\u00eang c\u1ee7a n\u01b0\u1edbc.","B. Tr\u1ecdng l\u01b0\u1ee3ng ri\u00eang c\u1ee7a v\u1eadt nh\u1ecf h\u01a1n trong l\u01b0\u1ee3ng ri\u00eang c\u1ee7a n\u01b0\u1edbc.","C. L\u1ef1c \u0111\u1ea9y \u00c1c-si-m\u00e9t l\u1edbn h\u01a1n tr\u1ecdng l\u01b0\u1ee3ng c\u1ee7a v\u1eadt.","D. L\u1ef1c \u0111\u1ea9y \u00c1c-si-m\u00e9t nh\u1ecf h\u01a1n tr\u1ecdng l\u01b0\u1ee3ng c\u1ee7a v\u1eadt."],"hint":"","explain":"<span class='basic_left'>\u0110\u1ec3 m\u1ed9t v\u1eadt \u0111\u1eb7c, kh\u00f4ng th\u1ea5m n\u01b0\u1edbc, ch\u1ec9 ch\u00ecm m\u1ed9t ph\u1ea7n trong n\u01b0\u1edbc th\u00ec tr\u1ecdng l\u01b0\u1ee3ng ri\u00eang c\u1ee7a v\u1eadt nh\u1ecf h\u01a1n trong l\u01b0\u1ee3ng ri\u00eang c\u1ee7a n\u01b0\u1edbc.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":1}]}],"id_ques":2648},{"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":"Treo m\u1ed9t v\u1eadt \u1edf ngo\u00e0i kh\u00f4ng kh\u00ed v\u00e0o l\u1ef1c k\u1ebf, l\u1ef1c k\u1ebf ch\u1ec9 2,1N. Nh\u00fang ch\u00ecm v\u1eadt \u0111\u00f3 v\u00e0o n\u01b0\u1edbc th\u00ec s\u1ed1 ch\u1ec9 c\u1ee7a l\u1ef1c k\u1ebf gi\u1ea3m 0,2N. H\u1ecfi ch\u1ea5t l\u00e0m v\u1eadt \u0111\u00f3 c\u00f3 tr\u1ecdng l\u01b0\u1ee3ng ri\u00eang l\u1edbn g\u1ea5p bao nhi\u00eau l\u1ea7n tr\u1ecdng l\u01b0\u1ee3ng ri\u00eang c\u1ee7a n\u01b0\u1edbc? Bi\u1ebft tr\u1ecdng l\u01b0\u1ee3ng ri\u00eang c\u1ee7a n\u01b0\u1edbc l\u00e0 10 000N\/${{m}^{3}}$.","select":["A. 6 l\u1ea7n.","B. 10 l\u1ea7n.","C. 10,5 l\u1ea7n.","D. 8 l\u1ea7n."],"hint":"","explain":"<span class='basic_left'>Khi nh\u00fang ch\u00ecm v\u1eadt v\u00e0o n\u01b0\u1edbc, v\u1eadt ch\u1ecbu t\u00e1c d\u1ee5ng c\u1ee7a l\u1ef1c \u0111\u1ea9y Ac-si-m\u00e9t n\u00ean s\u1ed1 ch\u1ec9 c\u1ee7a l\u1ef1c k\u1ebf gi\u1ea3m 0,2N, t\u1ee9c l\u00e0 $F_A$ = 0,2N.<br\/>Ta c\u00f3 $F_A$ = V x d, trong \u0111\u00f3 d l\u00e0 tr\u1ecdng l\u01b0\u1ee3ng ri\u00eang c\u1ee7a n\u01b0\u1edbc, V l\u00e0 th\u1ec3 t\u00edch ph\u1ea7n n\u01b0\u1edbc b\u1ecb v\u1eadt chi\u1ebfm ch\u1ed7.<br\/> Th\u1ec3 t\u00edch c\u1ee7a v\u1eadt l\u00e0:<br\/>$V=\\dfrac{{{F}_{A}}}{d}=\\dfrac{0.2}{10000}=0.00002{{m}^{3}}$.<br\/>$d=\\dfrac{P}{V}=\\dfrac{2.1}{0.00002}=105000N\/{{m}^{3}}$. <br\/>T\u1ec9 s\u1ed1:$\\dfrac{d}{{{d}_{n}}}=10,5$ l\u1ea7n. Ch\u1ea5t l\u00e0m v\u1eadt l\u00e0 b\u1ea1c.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":2}]}],"id_ques":2649},{"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":"L\u1ef1c \u0111\u1ea9y \u00c1c-si-m\u00e9t c\u00f3 th\u1ec3 t\u00e1c d\u1ee5ng l\u00ean v\u1eadt n\u00e0o d\u01b0\u1edbi \u0111\u00e2y? ","select":["A. V\u1eadt ch\u00ecm ho\u00e0n to\u00e0n trong ch\u1ea5t l\u1ecfng.","B. V\u1eadt l\u01a1 l\u1eedng trong ch\u1ea5t l\u1ecfng.","C. V\u1eadt n\u1ed5i tr\u00ean m\u1eb7t ch\u1ea5t l\u1ecfng.","D. C\u1ea3 ba tr\u01b0\u1eddng h\u1ee3p tr\u00ean."],"hint":"","explain":"<span class='basic_left'>c\u1ea3 ba tr\u01b0\u1eddng h\u1ee3p \u0111\u1ec1u ch\u1ecbu t\u00e1c d\u1ee5ng c\u1ee7a l\u1ef1c \u0111\u1ea9y \u00c1c-si-m\u00e9t. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 D.<\/span><\/span> ","column":2}]}],"id_ques":2650},{"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 v\u1eadt \u0111\u01b0\u1ee3c m\u00f3c v\u00e0o l\u1ef1c k\u1ebf \u0111\u1ec3 \u0111o l\u1ef1c theo ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng. Khi v\u1eadt \u1edf trong kh\u00f4ng kh\u00ed, l\u1ef1c k\u1ebf ch\u1ec9 4,8N. Khi v\u1eadt ch\u00ecm trong n\u01b0\u1edbc, l\u1ef1c k\u1ebf ch\u1ec9 3,6N. Bi\u1ebft tr\u1ecdng l\u01b0\u1ee3ng ri\u00eang c\u1ee7a n\u01b0\u1edbc l\u00e0 104N\/${{m}^{3}}$. B\u1ecf qua l\u1ef1c \u0111\u1ea9y Ac-si-m\u00e9t c\u1ee7a kh\u00f4ng kh\u00ed. Th\u1ec3 t\u00edch c\u1ee7a v\u1eadt n\u1eb7ng l\u00e0: ","select":["A. 480${c{m}^{3}}$.","B. 360${c{m}^{3}}$.","C. 120${c{m}^{3}}$.","D. 20${c{m}^{3}}$."],"hint":"","explain":"<span class='basic_left'>L\u1ef1c \u0111\u1ea9y Ac-si-met t\u00e1c d\u1ee5ng l\u00ean v\u1eadt:<br\/>$F_A$ = P \u2013 P\u2019 = 4,8 \u2013 3,6 = 1,2N<br\/>Th\u1ec3 t\u00edch v\u1eadt:<br\/>$V=\\dfrac{{{F}_{A}}}{d}=\\dfrac{1,2}{{{10}^{4}}}{{m}^{3}}=120c{{m}^{3}}$. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":2}]}],"id_ques":2651},{"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":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/vatly/bai10/lv2/img\/h13.jpg'\/><\/center>C\u00f3 2 v\u1eadt: V\u1eadt M b\u1eb1ng s\u1eaft, v\u1eadt N b\u1eb1ng nh\u00f4m c\u00f3 c\u00f9ng kh\u1ed1i l\u01b0\u1ee3ng. Hai v\u1eadt n\u00e0y treo v\u00e0o 2 \u0111\u1ea7u c\u1ee7a thanh CD( CO = OD), nh\u01b0 h\u00ecnh v\u1ebd. N\u1ebfu nh\u00fang ng\u1eadp c\u1ea3 2 v\u1eadt v\u00e0o trong r\u01b0\u1ee3u th\u00ec thanh CD s\u1ebd:","select":["A. V\u1eabn c\u00e2n b\u1eb1ng.","B. Nghi\u00eang v\u1ec1 b\u00ean tr\u00e1i.","C. Nghi\u00eang v\u1ec1 b\u00ean ph\u1ea3i.","D. Nghi\u00eang v\u1ec1 ph\u00eda th\u1ecfi \u0111\u01b0\u1ee3c nh\u00fang s\u00e2u h\u01a1n trong r\u01b0\u1ee3u."],"hint":"","explain":"<span class='basic_left'>V\u00ec qu\u1ea3 n\u1eb7ng N l\u1edbn h\u01a1n n\u00ean ch\u1ecbu t\u00e1c d\u1ee5ng c\u1ee7a l\u1ef1c Ac-si-m\u00e9t l\u1edbn h\u01a1n, n\u00ean c\u00e2n nghi\u00eang v\u1ec1 b\u00ean tr\u00e1i. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":2}]}],"id_ques":2652},{"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":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/vatly/bai10/lv2/img\/h14.jpg'\/><\/center>M\u1ed9t \u1ed1ng ch\u1eef U ch\u1ee9a n\u01b0\u1edbc, hai nh\u00e1nh \u0111\u01b0\u1ee3c h\u00fat h\u1ebft kh\u00f4ng kh\u00ed v\u00e0 h\u00e0n k\u00edn \u1edf 2 \u0111\u1ea7u. Cho \u1ed1ng ch\u1eef U nghi\u00eang v\u1ec1 ph\u00eda ph\u1ea3i th\u00ec:","select":["A. M\u1ef1c n\u01b0\u1edbc \u1edf nh\u00e1nh M th\u1ea5p h\u01a1n nh\u00e1nh N.","B. M\u1ef1c n\u01b0\u1edbc \u1edf nh\u00e1nh M cao h\u01a1n nh\u00e1nh N.","C. M\u1ef1c n\u01b0\u1edbc \u1edf nh\u00e1nh M b\u1eb1ng m\u1ef1c n\u01b0\u1edbc \u1edf nh\u00e1nh N.","D. Kh\u00f4ng so s\u00e1nh \u0111\u01b0\u1ee3c m\u1ef1c n\u01b0\u1edbc \u1edf 2 nh\u00e1nh."],"hint":"","explain":"<span class='basic_left'>V\u00ec \u00e1p su\u1ea5t ph\u1ea7n kh\u00ed \u1edf b\u00ean trong nh\u00e1nh N \u0111\u1ea9y kh\u00f4ng cho n\u01b0\u1edbc d\u00e2ng l\u00ean n\u1eefa, d\u1eabn \u0111\u1ebfn n\u01b0\u1edbc b\u00ean nh\u00e1nh M s\u1ebd cao h\u01a1n. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":1}]}],"id_ques":2653},{"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/bai10/lv2/img\/h15.jpg'\/><\/center>Ta bi\u1ebft c\u00f4ng th\u1ee9c t\u00ednh l\u1ef1c \u0111\u1ea9y Acsim\u00e9t l\u00e0 $F_A$= d x V. \u1ede h\u00ecnh v\u1ebd b\u00ean th\u00ec V l\u00e0 th\u1ec3 t\u00edch n\u00e0o?","select":["A. Th\u1ec3 t\u00edch to\u00e0n b\u1ed9 v\u1eadt.","B. Th\u1ec3 t\u00edch ch\u1ea5t l\u1ecfng.","C. Th\u1ec3 t\u00edch ph\u1ea7n ch\u00ecm c\u1ee7a v\u1eadt.","D. Th\u1ec3 t\u00edch ph\u1ea7n n\u1ed5i c\u1ee7a v\u1eadt."],"hint":"","explain":"<span class='basic_left'>V l\u00e0 th\u1ec3 t\u00edch ph\u1ea7n ch\u00ecm c\u1ee7a v\u1eadt. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":2}]}],"id_ques":2654},{"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\u00f3c 1 qu\u1ea3 n\u1eb7ng v\u00e0o l\u1ef1c k\u1ebf \u1edf ngo\u00e0i kh\u00f4ng kh\u00ed, l\u1ef1c k\u1ebf ch\u1ec9 30N. Nh\u00fang ch\u00ecm qu\u1ea3 n\u1eb7ng \u0111\u00f3 v\u00e0o trong n\u01b0\u1edbc s\u1ed1 ch\u1ec9 c\u1ee7a l\u1ef1c k\u1ebf thay \u0111\u1ed5i nh\u01b0 th\u1ebf n\u00e0o?","select":["A. T\u0103ng l\u00ean.","B. Gi\u1ea3m \u0111i.","C. Kh\u00f4ng thay \u0111\u1ed5i.","D. Ch\u1ec9 s\u1ed1 0"],"hint":"","explain":"<span class='basic_left'>Khi nh\u00fang v\u00e0o trong n\u01b0\u1edbc, v\u1eadt ch\u1ecbu t\u00e1c d\u1ee5ng c\u1ee7a l\u1ef1c \u0111\u1ea9y Ac-si-m\u00e9t d\u1eabn \u0111\u1ebfn l\u00e0m cho s\u1ed1 ch\u1ec9 c\u1ee7a l\u1ef1c k\u1ebf gi\u1ea3m \u0111i. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":2}]}],"id_ques":2655},{"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 qu\u1ea3 c\u1ea7u b\u1eb1ng \u0111\u1ed3ng \u0111\u01b0\u1ee3c treo v\u00e0o l\u1ef1c k\u1ebf th\u00ec l\u1ef1c k\u1ebf ch\u1ec9 4,45N. Nh\u00fang ch\u00ecm qu\u1ea3 c\u1ea7u v\u00e0o r\u01b0\u1ee3u th\u00ec l\u1ef1c k\u1ebf ch\u1ec9 bao nhi\u00eau? Bi\u1ebft ${{d}_{ruou}}=8000N\/{{m}^{3}}$ v\u00e0 ${{d}_{dong}}=89000N\/{{m}^{3}}$. ","select":["A. 4,45N.","B. 4,25N.","C. 4,15N.","D. 4,05N."],"hint":"","explain":"<span class='basic_left'>Th\u1ec3 t\u00edch c\u1ee7a qu\u1ea3 c\u1ea7u: $V=\\dfrac{4,45}{89000}=0,00005{{m}^{3}}$<br\/>L\u1ef1c \u0111\u1ea9y Ac-si-met khi nh\u00fang qu\u1ea3 c\u1ea7u v\u00e0o r\u01b0\u1ee3u l\u00e0:<br\/>${{F}_{A}}=V\\times{{d}_{ruou}}$ =0,00005\\times 8000=0,4N$<br\/>L\u1ef1c k\u1ebf ch\u1ec9 l\u00e0: $4,45-0,4 = 4,05N$ .<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 D.<\/span><\/span> ","column":2}]}],"id_ques":2656},{"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 v\u1eadt \u0111\u1eb7c treo v\u00e0o 1 l\u1ef1c k\u1ebf, \u1edf ngo\u00e0i kh\u00f4ng kh\u00ed ch\u1ec9 3,56N. Nh\u00fang ch\u00ecm v\u1eadt \u0111\u00f3 v\u00e0o n\u01b0\u1edbc th\u00ec s\u1ed1 ch\u1ec9 c\u1ee7a l\u1ef1c k\u1ebf gi\u1ea3m 0,4N. H\u1ecfi v\u1eadt \u0111\u00f3 \u0111\u01b0\u1ee3c l\u00e0m b\u1eb1ng ch\u1ea5t g\u00ec?","select":["A. \u0110\u1ed3ng.","B. S\u1eaft.","C. Ch\u00ec.","D. Nh\u00f4m."],"hint":"","explain":"<span class='basic_left'>T\u1ef7 l\u1ec7 kh\u1ed1i l\u01b0\u1ee3ng ri\u00eang c\u1ee7a ch\u1ea5t \u0111\u00f3 so v\u1edbi n\u01b0\u1edbc l\u00e0: $\\dfrac{3,56}{0,4}=8,9$ <br\/>V\u1eady v\u1eadt \u0111\u00f3 \u0111\u01b0\u1ee3c l\u00e0 b\u1eb1ng \u0110\u1ed3ng c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng ri\u00eang l\u00e0: 8,9g\/${c{m}^{3}}$ <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span><\/span> ","column":2}]}],"id_ques":2657},{"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":"Ba v\u1eadt l\u00e0m b\u1eb1ng ba ch\u1ea5t kh\u00e1c nhau l\u00e0 s\u1ee9 (c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng ri\u00eang l\u00e0 2300kg\/${{m}^{3}}$ ), nh\u00f4m (c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng ri\u00eang l\u00e0 2700kg\/${{m}^{3}}$ ), s\u1eaft (c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng ri\u00eang l\u00e0 7800kg\/${{m}^{3}}$ ) c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng b\u1eb1ng nhau, khi nh\u00fang ch\u00fang ng\u1eadp v\u00e0o n\u01b0\u1edbc th\u00ec \u0111\u1ed9 l\u1edbn l\u1ef1c \u0111\u1ea9y c\u1ee7a n\u01b0\u1edbc t\u00e1c d\u1ee5ng v\u00e0o:","select":["A. S\u1eaft l\u1edbn nh\u1ea5t, s\u1ee9 nh\u1ecf nh\u1ea5t.","B. Ba v\u1eadt nh\u01b0 nhau.","C. S\u1ee9 l\u1edbn nh\u1ea5t, s\u1eaft nh\u1ecf nh\u1ea5t.","D. S\u1eaft l\u1edbn nh\u1ea5t, nh\u00f4m nh\u1ecf nh\u1ea5t."],"hint":"","explain":"<span class='basic_left'>C\u00f3 c\u00f9ng m\u1ed9t kh\u1ed1i l\u01b0\u1ee3ng nh\u01b0 nhau, v\u1eadt n\u00e0o c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng ri\u00eang nh\u1ecf h\u01a1n th\u00ec s\u1ebd c\u00f3 th\u1ec3 t\u00edch l\u01a1n h\u01a1n, v\u00e0 s\u1ebd ch\u1ecbu t\u00e1c d\u1ee5ng c\u1ee7a l\u1ef1c \u0111\u1ea9y Ac-si-m\u00e9t l\u1edbn h\u01a1n.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":2}]}],"id_ques":2658},{"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":"Ba v\u1eadt l\u00e0m b\u1eb1ng ba ch\u1ea5t kh\u00e1c nhau l\u00e0 s\u1ee9 (c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng ri\u00eang l\u00e0 2300kg\/${{m}^{3}}$ ), nh\u00f4m (c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng ri\u00eang l\u00e0 2700kg\/${{m}^{3}}$ ), s\u1eaft (c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng ri\u00eang l\u00e0 7800kg\/${{m}^{3}}$ ) c\u00f3 h\u00ecnh d\u1ea1ng kh\u00e1c nhau nh\u01b0ng th\u1ec3 t\u00edch b\u1eb1ng nhau khi nh\u00fang ch\u00fang ng\u1eadp v\u00e0o n\u01b0\u1edbc th\u00ec \u0111\u1ed9 l\u1edbn l\u1ef1c \u0111\u1ea9y c\u1ee7a n\u01b0\u1edbc t\u00e1c d\u1ee5ng v\u00e0o:","select":["A. S\u1eaft l\u1edbn nh\u1ea5t, s\u1ee9 nh\u1ecf nh\u1ea5t.","B. Ba v\u1eadt nh\u01b0 nhau.","C. S\u1ee9 l\u1edbn nh\u1ea5t, s\u1eaft nh\u1ecf nh\u1ea5t.","D. S\u1eaft l\u1edbn nh\u1ea5t, nh\u00f4m nh\u1ecf nh\u1ea5t."],"hint":"","explain":"<span class='basic_left'>L\u1ef1c \u0111\u1ea9y \u00c1c-si-m\u00e9t l\u00e0 nh\u01b0 nhau v\u1edbi nh\u1eefng v\u1eadt c\u00f3 th\u1ec3 t\u00edch ch\u00ecm trong n\u01b0\u1edbc nh\u01b0 nhau.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":2}]}],"id_ques":2659}],"lesson":{"save":0,"level":2}}