{"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":"\u0110i\u1ec1u n\u00e0o l\u00e0 \u0111\u00fang khi n\u00f3i v\u1ec1 \u00e1p su\u1ea5t c\u1ee7a ch\u1ea5t l\u1ecfng?","select":["A. Ch\u1ea5t l\u1ecfng g\u00e2y ra \u00e1p su\u1ea5t theo ph\u01b0\u01a1ng ngang.","B. Ch\u1ea5t l\u1ecfng g\u00e2y ra \u00e1p su\u1ea5t theo m\u1ecdi ph\u01b0\u01a1ng l\u00ean \u0111\u00e1y b\u00ecnh, th\u00e0nh b\u00ecnh v\u00e0 c\u00e1c v\u1eadt \u1edf trong n\u00f3.","C. Ch\u1ea5t l\u1ecfng g\u00e2y ra \u00e1p su\u1ea5t theo ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng, h\u01b0\u1edbng t\u1eeb d\u01b0\u1edbi l\u00ean tr\u00ean.","D. Ch\u1ea5t l\u1ecfng ch\u1ec9 g\u00e2y ra \u00e1p su\u1ea5t t\u1ea1i nh\u1eefng \u0111i\u1ec3m \u1edf \u0111\u00e1y b\u00ecnh ch\u1ee9a."],"hint":"","explain":"<span class='basic_left'>Ch\u1ea5t l\u1ecfng kh\u00f4ng ch\u1ec9 g\u00e2y ra \u00e1p su\u1ea5t l\u00ean th\u00e0nh b\u00ecnh m\u00e0 l\u00ean c\u1ea3 \u0111\u00e1y b\u00ecnh v\u00e0 c\u00e1c v\u1eadt \u1edf trong l\u00f2ng ch\u1ea5t l\u1ecfng.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":1}]}],"id_ques":2800},{"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":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/vatly/bai8/lv2/img\/h2.jpg'\/><\/center>B\u1ed1n b\u00ecnh trong h\u00ecnh A, B, C, D d\u01b0\u1edbi \u0111\u00e2y c\u00f9ng \u0111\u1ef1ng n\u01b0\u1edbc. \u00c1p su\u1ea5t c\u1ee7a n\u01b0\u1edbc l\u00ean \u0111\u00e1y b\u00ecnh n\u00e0o l\u00e0 l\u1edbn nh\u1ea5t? ","select":["A. B\u00ecnh A.","B. B\u00ecnh B.","C. B\u00ecnh C.","D. B\u00ecnh D."],"hint":"","explain":"<span class='basic_left'>Ta c\u00f3 \u00e1p su\u1ea5t ch\u1ea5t l\u1ecfng : $p=d\\times h$. <br\/> Do \u1edf c\u1ea3 4 b\u00ecnh \u0111\u1ec1u \u0111\u1ef1ng c\u00f9ng 1 ch\u1ea5t l\u1ecfng n\u00ean tr\u1ecdng l\u01b0\u1ee3ng ri\u00eang c\u1ee7a n\u00f3 b\u1eb1ng nhau. M\u00e0 \u1edf b\u00ecnh A c\u00f3 c\u1ed9t n\u01b0\u1edbc cao h\u01a1n n\u00ean \u00e1p su\u1ea5t c\u1ee7a c\u1ed9t n\u01b0\u1edbc l\u00ean \u0111\u00e1y b\u00ecnh A l\u00e0 cao nh\u1ea5t.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span><\/span> ","column":2}]}],"id_ques":2801},{"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/bai8/lv2/img\/h2.jpg'\/><\/center>B\u1ed1n b\u00ecnh trong h\u00ecnh A, B, C, D d\u01b0\u1edbi \u0111\u00e2y c\u00f9ng \u0111\u1ef1ng n\u01b0\u1edbc. \u00c1p su\u1ea5t c\u1ee7a n\u01b0\u1edbc l\u00ean \u0111\u00e1y b\u00ecnh n\u00e0o l\u00e0 nh\u1ecf nh\u1ea5t? ","select":["A. B\u00ecnh A.","B. B\u00ecnh B.","C. B\u00ecnh C.","D. B\u00ecnh D."],"hint":"","explain":"<span class='basic_left'>Ta c\u00f3 \u00e1p su\u1ea5t ch\u1ea5t l\u1ecfng : $p=d\\times h$. <br\/> Do \u1edf c\u1ea3 4 b\u00ecnh \u0111\u1ec1u \u0111\u1ef1ng c\u00f9ng 1 ch\u1ea5t l\u1ecfng n\u00ean tr\u1ecdng l\u01b0\u1ee3ng ri\u00eang c\u1ee7a n\u00f3 b\u1eb1ng nhau. M\u00e0 \u1edf b\u00ecnh C c\u00f3 c\u1ed9t n\u01b0\u1edbc th\u1ea5p nh\u1ea5t, n\u00ean \u00e1p su\u1ea5t c\u1ee7a c\u1ed9t n\u01b0\u1edbc l\u00ean \u0111\u00e1y b\u00ecnh C l\u00e0 th\u1ea5p nh\u1ea5t.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":2}]}],"id_ques":2802},{"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":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/vatly/bai8/lv2/img\/h4.jpg'\/><\/center>Hai b\u00ecnh A v\u00e0 B th\u00f4ng nhau. B\u00ecnh A \u0111\u1ef1ng d\u1ea7u, b\u00ecnh B \u0111\u1ef1ng n\u01b0\u1edbc t\u1edbi c\u00f9ng m\u1ed9t \u0111\u1ed9 cao. Khi m\u1edf kh\u00f3a K, n\u01b0\u1edbc v\u00e0 d\u1ea7u c\u00f3 ch\u1ea3y t\u1eeb b\u00ecnh n\u1ecd sang b\u00ecnh kia kh\u00f4ng? ","select":["A. Kh\u00f4ng, v\u00ec \u0111\u1ed9 cao c\u1ee7a c\u1ed9t ch\u1ea5t l\u1ecfng \u1edb hai b\u00ecnh b\u1eb1ng nhau.","B. D\u1ea7u ch\u1ea3y sang n\u01b0\u1edbc v\u00ec l\u01b0\u1ee3ng d\u1ea7u nhi\u1ec1u h\u01a1n.","C. D\u1ea7u ch\u1ea3y sang n\u01b0\u1edbc v\u00ec d\u1ea7u nh\u1eb9 h\u01a1n.","D. N\u01b0\u1edbc ch\u1ea3y sang d\u1ea7u v\u00ec \u00e1p su\u1ea5t c\u1ed9t n\u01b0\u1edbc l\u1edbn h\u01a1n \u00e1p su\u1ea5t c\u1ed9t d\u1ea7u do tr\u1ecdng l\u01b0\u1ee3ng ri\u00eang c\u1ee7a n\u01b0\u1edbc l\u1edbn h\u01a1n d\u1ea7u."],"hint":"","explain":"<span class='basic_left'>N\u01b0\u1edbc ch\u1ea3y sang d\u1ea7u v\u00ec \u00e1p su\u1ea5t c\u1ed9t n\u01b0\u1edbc l\u1edbn h\u01a1n \u00e1p su\u1ea5t c\u1ed9t d\u1ea7u do tr\u1ecdng l\u01b0\u1ee3ng ri\u00eang c\u1ee7a n\u01b0\u1edbc l\u1edbn h\u01a1n d\u1ea7u. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 D.<\/span><\/span> ","column":1}]}],"id_ques":2803},{"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 t\u00e0u ng\u1ea7m \u0111ang di chuy\u1ec3n d\u01b0\u1edbi bi\u1ec3n. \u00c1p k\u1ebf \u0111\u1eb7t \u1edf ngo\u00e0i v\u1ecf t\u00e0u ch\u1ec9 \u00e1p su\u1ea5t 2.020.000N\/${{m}^{2}}$. M\u1ed9t l\u00fac sau \u00e1p k\u1ebf ch\u1ec9 860.000N\/${{m}^{2}}$. T\u00ednh \u0111\u1ed9 s\u00e2u c\u1ee7a t\u00e0u ng\u1ea7m \u1edf hai th\u1eddi \u0111i\u1ec3m tr\u00ean bi\u1ebft tr\u1ecdng l\u01b0\u1ee3ng ri\u00eang c\u1ee7a n\u01b0\u1edbc bi\u1ec3n b\u1eb1ng 10.300N\/${{m}^{3}}$ .","select":["A. 196m; 83,5m.","B. 160m; 83,5m.","C. 169m; 85m.","D. 85m; 169m."],"hint":"","explain":"<span class='basic_left'>\u00c1p d\u1ee5ng c\u00f4ng th\u1ee9c: $p=h\\times d$<br\/>Ta c\u00f3: $h=\\dfrac{p}{d}$<br\/>\u0110\u1ed9 s\u00e2u c\u1ee7a t\u00e0u ng\u1ea7m \u1edf th\u1eddi \u0111i\u1ec3m tr\u01b0\u1edbc khi n\u1ed5i l\u00ean: ${{h}_{1}}=\\dfrac{{{p}_{1}}}{d}=\\dfrac{2020000}{10300}=196m$<br\/>\u0110\u1ed9 s\u00e2u c\u1ee7a t\u00e0u ng\u1ea7m \u1edf th\u1eddi \u0111i\u1ec3m sau khi n\u1ed5i l\u00ean: ${{h}_{2}}=\\dfrac{{{p}_{2}}}{d}=\\dfrac{860000}{10300}=83,5m$<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span><\/span> ","column":2}]}],"id_ques":2804},{"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 \u1ed1ng th\u1ee7y tinh h\u00ecnh tr\u1ee5 \u0111\u1ef1ng ch\u1ea5t l\u1ecfng \u0111ang \u0111\u01b0\u1ee3c \u0111\u1eb7t th\u1eb3ng \u0111\u1ee9ng. N\u1ebfu nghi\u00eang \u1ed1ng \u0111i sao cho ch\u1ea5t l\u1ecfng kh\u00f4ng ch\u1ea3y ra kh\u1ecfi \u1ed1ng, th\u00ec \u00e1p su\u1ea5t ch\u1ea5t l\u1ecfng g\u00e2y ra \u1edf \u0111\u00e1y b\u00ecnh? ","select":["A. T\u0103ng.","B. Gi\u1ea3m.","C. Kh\u00f4ng \u0111\u1ed5i.","D. B\u1eb1ng kh\u00f4ng"],"hint":"","explain":"<span class='basic_left'>Khi nghi\u00eang \u1ed1ng \u0111i, chi\u1ec1u cao c\u1ed9t n\u01b0\u1edbc trong \u1ed1ng s\u1ebd gi\u1ea3m d\u1eabn \u0111\u1ebfn \u00e1p su\u1ea5t gi\u1ea3m. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":2}]}],"id_ques":2805},{"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 b\u00ecnh th\u00f4ng nhau ch\u1ee9a n\u01b0\u1edbc bi\u1ec3n. Ng\u01b0\u1eddi ta \u0111\u1ed5 th\u00eam x\u0103ng v\u00e0o m\u1ed9t nh\u00e1nh. Hai m\u1eb7t tho\u00e1ng \u1edf hai nh\u00e1nh ch\u00eanh l\u1ec7ch nhau 18mm. T\u00ednh \u0111\u1ed9 cao c\u1ee7a c\u1ed9t x\u0103ng. Cho bi\u1ebft tr\u1ecdng l\u01b0\u1ee3ng ri\u00eang c\u1ee7a n\u01b0\u1edbc bi\u1ec3n l\u00e0 10300N\/${{m}^{3}}$ v\u00e0 c\u1ee7a x\u0103ng l\u00e0 7000N\/${{m}^{3}}$ ","select":["A. 54mm.","B. 56mm.","C. 58mm.","D. 60mm."],"hint":"","explain":"<span class='basic_left'>h = 18mm, ${{d}_{1}}=7000N\/{{m}^{3}}$ , ${{d}_{2}}=10300N\/{{m}^{3}}$. <br\/>X\u00e9t 2 \u0111i\u1ec3m A, B trong 2 nh\u00e1nh n\u1eb1m trong c\u00f9ng 1 m\u1eb7t ph\u1eb3ng ngang tr\u00f9ng v\u1edbi m\u1eb7t ph\u00e2n c\u00e1ch gi\u1eefa x\u0103ng v\u00e0 n\u01b0\u1edbc bi\u1ec3n.<br\/>Ta c\u00f3: ${{P}_{A}}$ = ${{P}_{B}}$ m\u1eb7t kh\u00e1c ${{P}_{A}}$ = ${{h}_{1}}\\times {{d}_{1}}$ , ${{P}_{B}}$ = ${{h}_{2}}\\times {{d}_{2}}$ <br\/>\u21d2 ${{h}_{1}}\\times {{d}_{1}}={{h}_{2}}\\times {{d}_{2}}$ <br\/>${{h}_{2}}-{{h}_{1}}=h$ \u21d2 ${{h}_{1}}\\times {{d}_{1}}={{d}_{2}}\\times ({{h}_{1}}-h)$ <br\/>$({{d}_{2}}-{{d}_{1}})\\times {{h}_{1}}={{d}_{2}}\\times h$ <br\/>${{h}_{1}}=\\dfrac{{{d}_{2}}\\times h}{{{d}_{2}}-{{d}_{1}}}=\\dfrac{10300\\times 18}{10300-7000}=56mm$<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":2}]}],"id_ques":2806},{"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/bai8/lv2/img\/h8.jpg'\/><\/center>H\u00e3y so s\u00e1nh \u00e1p su\u1ea5t t\u1ea1i c\u00e1c \u0111i\u1ec3m M, N v\u00e0 Q, trong b\u00ecnh ch\u1ee9a ch\u1ea5t l\u1ecfng trong h\u00ecnh v\u1ebd? ","select":["A. ${{p}_{M}}$ < ${{p}_{N}}$ < ${{p}_{Q}}$","B. ${{p}_{M}}$ = ${{p}_{N}}$ = ${{p}_{Q}}$","C. ${{p}_{M}}$ > ${{p}_{N}}$ > ${{p}_{Q}}$","D. ${{p}_{M}}$ < ${{p}_{Q}}$ < ${{p}_{N}}$"],"hint":"","explain":"<span class='basic_left'>\u00c1p su\u1ea5t ch\u1ea5t l\u1ecfng ph\u1ee5 thu\u1ed9c v\u00e0o chi\u1ec1u cao \u0111\u1ebfn m\u1eb7t tho\u00e1ng, n\u00ean \u0111i\u1ec3m n\u00e0o c\u00e0ng \u1edf d\u01b0\u1edbi th\u1ea5p so v\u1edbi m\u1eb7t tho\u00e1ng th\u00ec \u00e1p xu\u1ea5t c\u00e0ng l\u1edbn. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":2}]}],"id_ques":2807},{"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":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/vatly/bai8/lv2/img\/h9.jpg'\/><\/center>H\u00ecnh v\u1ebd m\u1eb7t c\u1eaft c\u1ee7a m\u1ed9t con \u0111\u00ea ch\u1eafn n\u01b0\u1edbc cho th\u1ea5y m\u1eb7t \u0111\u00ea bao gi\u1edd c\u0169ng h\u1eb9p h\u01a1n ch\u00e2n \u0111\u00ea. \u0110\u00ea \u0111\u01b0\u1ee3c c\u1ea5u t\u1ea1o nh\u01b0 th\u1ebf nh\u1eb1m \u0111\u1ec3: ","select":["A. Ti\u1ebft ki\u1ec7m \u0111\u1ea5t \u0111\u1eafp \u0111\u00ea.","B. L\u00e0m th\u00e0nh m\u1eb7t ph\u0103ng nghi\u00eang, t\u1ea1o \u0111i\u1ec1u ki\u1ec7n thu\u1eadn l\u1ee3i cho ng\u01b0\u1eddi mu\u1ed1n \u0111i l\u00ean m\u1eb7t \u0111\u00ea.","C. C\u00f3 th\u1ec3 tr\u1ed3ng c\u1ecf tr\u00ean \u0111\u00ea, gi\u1eef cho \u0111\u00ea kh\u1ecfi b\u1ecb l\u1edf.","D. Ch\u00e2n \u0111\u00ea c\u00f3 th\u1ec3 ch\u1ecbu \u0111\u01b0\u1ee3c \u00e1p su\u1ea5t l\u1edbn h\u01a1n nhi\u1ec1u so v\u1edbi m\u1eb7t \u0111\u1ebf."],"hint":"","explain":"<span class='basic_left'>V\u00ec ch\u00e2n \u0111\u00ea ch\u1ecbu \u00e1p su\u1ea5t c\u1ee7a n\u01b0\u1edbc t\u00e1c \u0111\u1ed9ng v\u00e0o l\u1edbn h\u01a1n m\u1eb7t \u0111\u00ea n\u00ean c\u1ea7n \u0111\u1eafp ch\u00e2n \u0111\u00ea to h\u01a1n m\u1eb7t \u0111\u00ea. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 D.<\/span><\/span> ","column":1}]}],"id_ques":2808},{"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\u1ea1i sao khi l\u1eb7n ta lu\u00f4n c\u1ea3m th\u1ea5y t\u1ee9c ng\u1ef1c v\u00e0 c\u00e0ng l\u1eb7n s\u00e2u th\u00ec c\u1ea3m gi\u00e1c t\u1ee9c ng\u1ef1c c\u00e0ng t\u0103ng?","select":["A. \u00c1p su\u1ea5t c\u1ee7a n\u01b0\u1edbc t\u0103ng.","B. \u00c1p su\u1ea5t c\u1ee7a n\u01b0\u1edbc gi\u1ea3m.","C. \u00c1p su\u1ea5t kh\u00f4ng kh\u00ed t\u0103ng.","D. \u00c1p su\u1ea5t kh\u00f4ng kh\u00ed gi\u1ea3m."],"hint":"","explain":"<span class='basic_left'>V\u00ec c\u00e0ng xu\u1ed1ng s\u00e2u d\u01b0\u1edbi n\u01b0\u1edbc th\u00ec \u00e1p l\u1ef1c n\u01b0\u1edbc t\u00e1c d\u1ee5ng l\u00ean ng\u01b0\u1eddi c\u00e0ng l\u1edbn, d\u1eabn \u0111\u1ebfn ta c\u00e0ng c\u1ea3m th\u1ea5y t\u1ee9c ng\u1ef1c. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span><\/span> ","column":2}]}],"id_ques":2809},{"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 chi\u1ebfc t\u00e0u b\u1ecb th\u1ee7ng m\u1ed9t l\u1ed7 \u1edf \u0111\u1ed9 s\u00e2u 2,8m. Ng\u01b0\u1eddi ta \u0111\u1eb7t m\u1ed9t mi\u1ebfng v\u00e1 \u00e1p v\u00e0o l\u1ed7 th\u1ee7ng t\u1eeb ph\u00eda trong. H\u1ecfi c\u1ea7n m\u1ed9t l\u1ef1c t\u1ed1i thi\u1ec3u b\u1eb1ng bao nhi\u00eau \u0111\u1ec3 gi\u1eef mi\u1ebfng v\u00e1 n\u1ebfu l\u1ed7 th\u1ee7ng r\u1ed9ng 150${c{m}^{2}}$ v\u00e0 tr\u1ecdng l\u01b0\u1ee3ng ri\u00eang c\u1ee7a n\u01b0\u1edbc l\u00e0 10000N\/${{m}^{3}}$ ","select":["A. 240N","B. 420N","C. 320N","D. 230N"],"hint":"","explain":"<span class='basic_left'>\u00c1p su\u1ea5t do n\u01b0\u1edbc g\u00e2y ra t\u1ea1i ch\u1ed7 th\u1ee7ng l\u00e0: $p=d\\times h=10000\\times 2,8=28000N\/{{m}^{2}}$<br\/>L\u1ef1c t\u1ed1i thi\u1ec3u \u0111\u1ec3 gi\u1eef mi\u1ebfng v\u00e1 l\u00e0: $F=p\\times s=28000\\times 0,015=420N$ <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":2}]}],"id_ques":2810},{"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\u00e2u n\u00e0o sau \u0111\u00e2y n\u00f3i v\u1ec1 \u00e1p su\u1ea5t ch\u1ea5t l\u1ecfng l\u00e0 \u0111\u00fang ? ","select":["A. Ch\u1ea5t l\u1ecfng ch\u1ec9 g\u00e2y \u00e1p su\u1ea5t theo ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng t\u1eeb tr\u00ean xu\u1ed1ng.","B. \u00c1p su\u1ea5t ch\u1ea5t l\u1ecfng ch\u1ec9 ph\u1ee5 thu\u1ed9c v\u00e0o b\u1ea3n ch\u1ea5t c\u1ee7a ch\u1ea5t l\u1ecfng.","C. Ch\u1ea5t l\u1ecfng g\u00e2y \u00e1p su\u1ea5t theo m\u1ecdi ph\u01b0\u01a1ng.","D. \u00c1p su\u1ea5t ch\u1ea5t l\u1ecfng ch\u1ec9 ph\u1ee5 thu\u1ed9c v\u00e0o chi\u1ec1u cao c\u1ee7a ch\u1ea5t l\u1ecfng."],"hint":"","explain":"<span class='basic_left'>\u00c1p su\u1ea5t c\u1ee7a ch\u1ea5t l\u1ecfng t\u00e1c d\u1ee5ng l\u00ean b\u1ec1 m\u1eb7t \u0111\u1eb7t trong ch\u1ea5t l\u1ecfng theo m\u1ecdi ph\u01b0\u01a1ng. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":1}]}],"id_ques":2811},{"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 b\u00ecnh c\u00f3 ti\u1ebft di\u1ec7n b\u1eb1ng nhau. B\u00ecnh th\u1ee9 nh\u1ea5t ch\u1ee9a ch\u1ea5t l\u1ecfng c\u00f3 tr\u1ecdng l\u01b0\u1ee3ng ri\u00eang ${{d}_{1}}$, chi\u1ec1u cao ${{h}_{1}}$; b\u00ecnh th\u1ee9 hai ch\u1ee9a ch\u1ea5t l\u1ecfng c\u00f3 tr\u1ecdng l\u01b0\u1ee3ng ri\u00eang ${{d}_{2}}$ = 1,5${{d}_{1}}$, chi\u1ec1u cao ${{h}_{2}}$ = 0,6${{h}_{1}}$. N\u1ebfu g\u1ecdi \u00e1p su\u1ea5t ch\u1ea5t l\u1ecfng t\u00e1c d\u1ee5ng l\u00ean \u0111\u00e1y b\u00ecnh 1 l\u00e0 ${{p}_{1}}$, l\u00ean \u0111\u00e1y b\u00ecnh b\u00ecnh 2 l\u00e0 ${{p}_{2}}$ th\u00ec: ","select":["A. ${{p}_{2}}$ = 3${{p}_{1}}$.","B. ${{p}_{2}}$ = 0,9${{p}_{1}}$.","C. ${{p}_{2}}$ = 9${{p}_{1}}$.","D. ${{p}_{2}}$ = 0,4${{p}_{1}}$."],"hint":"","explain":"<span class='basic_left'>${{p}_{1}}={{d}_{1}}\\times {{h}_{1}}$<br\/>${{p}_{2}}={{d}_{2}}\\times {{h}_{2}}$<br\/>L\u1eadp t\u1ec9 s\u1ed1: $\\dfrac{{{p}_{2}}}{{{p}_{1}}}=\\dfrac{{{d}_{2}}\\times {{h}_{2}}}{{{d}_{1}}\\times {{h}_{1}}}=\\dfrac{1,5{{d}_{1}}\\times 0,6{{h}_{1}}}{{{d}_{1}}\\times {{h}_{1}}}=0,9$. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":2}]}],"id_ques":2812},{"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 b\u00ecnh th\u00f4ng nhau g\u1ed3m 2 nh\u00e1nh, nh\u00e1nh l\u1edbn c\u00f3 ti\u1ebft di\u1ec7n l\u1edbn g\u1ea5p \u0111\u00f4i nh\u00e1nh nh\u1ecf. Khi ch\u01b0a m\u1edf kh\u00f3a T, chi\u1ec1u cao c\u1ee7a c\u1ed9t n\u01b0\u1edbc \u1edf nh\u00e1nh l\u1edbn l\u00e0 30cm. T\u00ecm chi\u1ec1u cao c\u1ed9t n\u01b0\u1edbc \u1edf 2 nh\u00e1nh sau khi \u0111\u00e3 m\u1edf kh\u00f3a T v\u00e0 khi n\u01b0\u1edbc \u0111\u0103 \u0111\u1ee9ng y\u00ean. B\u1ecf qua th\u1ebf t\u00edch c\u1ee7a \u00f4ng n\u1ed1i hai nh\u00e1nh.","select":["A. 10cm.","B. 20cm.","C. 30cm.","D. 40cm."],"hint":"","explain":"<span class='basic_left'>G\u1ecdi di\u1ec7n t\u00edch ti\u1ebft di\u1ec7n c\u1ee7a \u1ed1ng nh\u1ecf l\u00e0 s, th\u00ec di\u1ec7n t\u00edch ti\u1ebft di\u1ec7n \u1ed1ng l\u1edbn l\u00e0 2S.<br\/>Sau khi m\u1edf kh\u00f3a T, c\u1ed9t n\u01b0\u1edbc \u1edf hai nh\u00e1nh c\u00f3 c\u00f9ng chi\u1ec1u cao h. Do th\u1ec3 t\u00edch n\u01b0\u1edbc trong b\u00ecnh th\u00f4ng nhau l\u00e0 kh\u00f4ng \u0111\u1ed5i n\u00ean ta c\u00f3:<br\/>2Sx30 = sxh + 2S. h<br\/>\u21d2 h = 20cm<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":2}]}],"id_ques":2813},{"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":"Khi th\u1ee3 l\u1eb7n l\u1eb7n xu\u1ed1ng bi\u1ec3n: ","select":["A. C\u00e0ng xu\u1ed1ng s\u00e2u \u00e1p su\u1ea5t t\u00e1c d\u1ee5ng l\u00ean th\u1ee3 l\u1eb7n c\u00e0ng t\u0103ng.","B. C\u00e0ng xu\u1ed1ng s\u00e2u \u00e1p su\u1ea5t t\u00e1c d\u1ee5ng l\u00ean th\u1ee3 l\u1eb7n c\u00e0ng gi\u1ea3m.","C. \u00c1p su\u1ea5t t\u00e1c d\u1ee5ng l\u00ean th\u1ee3 l\u1eb7n kh\u00f4ng ph\u1ee5 thu\u1ed9c v\u00e0o \u0111\u1ed9 s\u00e2u.","D. \u00c1p su\u1ea5t t\u00e1c d\u1ee5ng l\u1ebbn th\u1ee3 l\u1eb7n c\u00e0ng xa b\u1edd c\u00e0ng l\u1edbn."],"hint":"","explain":"<span class='basic_left'>Khi th\u1ee3 l\u1eb7n l\u1eb7n xu\u1ed1ng bi\u1ec3n, c\u00e0ng xu\u1ed1ng s\u00e2u \u00e1p su\u1ea5t t\u00e1c d\u1ee5ng l\u00ean th\u1ee3 l\u1eb7n c\u00e0ng t\u0103ng.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span><\/span> ","column":1}]}],"id_ques":2814},{"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":"\u00c1p su\u1ea5t m\u00e0 ch\u1ea5t l\u1ecfng t\u00e1c d\u1ee5ng l\u00ean m\u1ed9t \u0111i\u1ec3m ph\u1ee5 thu\u1ed9c:","select":["A. Kh\u1ed1i l\u01b0\u1ee3ng l\u1edbp ch\u1ea5t l\u1ecfng ph\u00eda tr\u00ean.","B. Tr\u1ecdng l\u01b0\u1ee3ng l\u1edbp ch\u1ea5t l\u1ecfng ph\u00eda tr\u00ean.","C. Th\u1ec3 t\u00edch l\u1edbp ch\u1ea5t l\u1ecfng ph\u00eda tr\u00ean.","D. \u0110\u1ed9 cao l\u1edbp ch\u1ea5t l\u1ecfng ph\u00eda tr\u00ean."],"hint":"","explain":"<span class='basic_left'>\u00c1p su\u1ea5t m\u00e0 ch\u1ea5t l\u1ecfng t\u00e1c d\u1ee5ng l\u00ean m\u1ed9t \u0111i\u1ec3m ph\u1ee5 thu\u1ed9c \u0111\u1ed9 cao l\u1edbp ch\u1ea5t l\u1ecfng ph\u00eda tr\u00ean. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 D.<\/span><\/span> ","column":1}]}],"id_ques":2815},{"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":"C\u00f4ng th\u1ee9c t\u00ednh \u00e1p su\u1ea5t ch\u1ea5t l\u1ecfng l\u00e0:","select":["A. $p =\\dfrac{d}{h}$.","B. p = d.h.","C. p = d.V.","D. $p =\\dfrac{h}{d}$."],"hint":"","explain":"<span class='basic_left'>C\u00f4ng th\u1ee9c t\u00ednh \u00e1p su\u1ea5t ch\u1ea5t l\u1ecfng l\u00e0: p = d.h. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":2}]}],"id_ques":2816},{"time":24,"part":[{"title":"","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":"Trong c\u00e1c k\u1ebft lu\u1eadn sau, k\u1ebft lu\u1eadn n\u00e0o kh\u00f4ng \u0111\u00fang \u0111\u1ed1i v\u1edbi b\u00ecnh th\u00f4ng nhau?","select":["A. B\u00ecnh th\u00f4ng nhau l\u00e0 b\u00ecnh c\u00f3 2 ho\u1eb7c nhi\u1ec1u nh\u00e1nh th\u00f4ng nhau.","B. Ti\u1ebft di\u1ec7n c\u1ee7a c\u00e1c nh\u00e1nh b\u00ecnh th\u00f4ng nhau ph\u1ea3i b\u1eb1ng nhau.","C. Trong b\u00ecnh th\u00f4ng nhau c\u00f3 th\u1ec3 ch\u1ee9a 1 ho\u1eb7c nhi\u1ec1u ch\u1ea5t l\u1ecfng kh\u00e1c nhau.","D. Trong b\u00ecnh th\u00f4ng nhau ch\u1ee9a c\u00f9ng 1 ch\u1ea5t l\u1ecfng \u0111\u1ee9ng y\u00ean, c\u00e1c m\u1ef1c ch\u1ea5t l\u1ecfng \u1edf c\u00e1c nh\u00e1nh lu\u00f4n \u1edf c\u00f9ng 1 \u0111\u1ed9 cao."],"hint":"","explain":"<span class='basic_left'> N\u1ebfu ti\u1ebft di\u1ec7n c\u1ee7a c\u00e1c nh\u00e1nh b\u00ecnh th\u00f4ng nhau b\u1eb1ng nhau th\u00ec kh\u00f4ng c\u00f2n t\u00e1c d\u1ee5ng bi\u1ebfn \u0111\u1ed5i l\u1ef1c n\u1eefa. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":1}]}],"id_ques":2817},{"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\u1ee5c n\u01b0\u1edbc \u0111\u00e1 \u0111ang n\u1ed5i trong b\u00ecnh n\u01b0\u1edbc. M\u1ef1c n\u01b0\u1edbc trong b\u00ecnh thay \u0111\u1ed5i nh\u01b0 th\u1ebf n\u00e0o khi c\u1ee5c n\u01b0\u1edbc \u0111\u00e1 tan h\u1ebft:","select":["A. T\u0103ng.","B. Gi\u1ea3m.","C. Kh\u00f4ng \u0111\u1ed5i.","D. Kh\u00f4ng x\u00e1c \u0111\u1ecbnh \u0111\u01b0\u1ee3c."],"hint":"","explain":"<span class='basic_left'>V\u00ec khi h\u00f3a r\u1eafn, n\u01b0\u1edbc t\u0103ng th\u1ec3 t\u00edch, tr\u1ecdng l\u01b0\u1ee3ng ri\u00eang b\u1ecb gi\u1ea3m, n\u00ean \u0111\u00e1 n\u1ed5i. Ph\u1ea7n \u0111\u00e1 ch\u00ecm trong n\u01b0\u1edbc c\u00f3 th\u1ec3 t\u00edch b\u1eb1ng ch\u00ednh th\u1ec3 t\u00edch c\u1ee7a l\u01b0\u1ee3ng n\u01b0\u1edbc \u0111\u00e3 h\u00f3a r\u1eafn th\u00e0nh vi\u00ean \u0111\u00e1. n\u00ean khi \u0111\u00e1 tan h\u1ebft th\u00ec th\u1ec3 t\u00edch n\u1eefa v\u1eabn kh\u00f4ng thay \u0111\u1ed5i. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":2}]}],"id_ques":2818},{"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/bai8/lv2/img\/h20.jpg'\/><\/center>Ba b\u00ecnh ch\u1ee9a c\u00f9ng 1 l\u01b0\u1ee3ng n\u01b0\u1edbc \u1edf $4{}^\\circ $. \u0110un n\u00f3ng c\u1ea3 3 b\u00ecnh l\u00ean c\u00f9ng 1 nhi\u1ec7t \u0111\u1ed9. So s\u00e1nh \u00e1p su\u1ea5t c\u1ee7a n\u01b0\u1edbc t\u00e1c d\u1ee5ng l\u00ean \u0111\u00e1y b\u00ecnh ta th\u1ea5y:","select":["A. $p_1$ = $p_2$ = $p_3$ .","B. $p_1$ > $p_2$ > $p_3$ .","C. $p_3$ > $p_2$ > $p_1$ .","D. $p_2$ > $p_3$ > $p_1$ ."],"hint":"","explain":"<span class='basic_left'>V\u00ec d\u1ef1a v\u00e0o h\u00ecnh d\u00e1ng c\u1ee7a b\u00ecnh, khi \u0111\u01b0\u1ee3c \u0111un n\u00f3ng \u0111\u1ebfn m\u1ed9t nhi\u1ec7t \u0111\u1ed9 nh\u1ea5t \u0111\u1ecbnh th\u00ec th\u1ec3 t\u00edch n\u01b0\u1edbc c\u1ee7a ba b\u00ecnh t\u0103ng nh\u01b0 nhau, nh\u01b0ng chi\u1ec1u cao c\u1ee7a b\u00ecnh n\u01b0\u1edbc kh\u00e1c nhau. Chi\u1ec1u cao c\u1ee7a n\u01b0\u1edbc trong b\u00ecnh 3 > chi\u1ec1u cao c\u1ee7a n\u01b0\u1edbc trong b\u00ecnh 2 > chi\u1ec1u cao c\u1ee7a n\u01b0\u1edbc trong b\u00ecnh 1.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":2}]}],"id_ques":2819}],"lesson":{"save":0,"level":2}}