Trọng lực và lực căng

Home Lớp 10 Vật lý 10 - Sách kết nối tri thức Bài 17. Trọng lực và lực căngBài tập trung bình

{"common":{"save":0,"post_id":"8520","level":2,"total":10,"point":10,"point_extra":0},"segment":[{"id":"7669","mon_id":"1158790","chapter_id":"1158796","post_id":"8520","question":"Nh\u1eadn xét nào sau \u0111ây sai<\/strong>?<\/p>","options":["A.<\/strong> Kh\u1ed1i l\u01b0\u1ee3ng c\u1ee7a m\u1ed9t v\u1eadt ch\u1ec9 l\u01b0\u1ee3ng ch\u1ea5t t\u1ea1o nên v\u1eadt \u0111ó.","B.<\/strong> Kh\u1ed1i l\u01b0\u1ee3ng c\u1ee7a m\u1ed9t v\u1eadt không thay \u0111\u1ed5i theo v\u1ecb trí \u0111\u1eb7t v\u1eadt.","C.<\/strong> Vì P = mg nên kh\u1ed1i l\u01b0\u1ee3ng và tr\u1ecdng l\u01b0\u1ee3ng c\u1ee7a v\u1eadt không thay \u0111\u1ed5i theo v\u1ecb trí \u0111\u1eb7t v\u1eadt.","D.<\/strong> Bi\u1ebft kh\u1ed1i l\u01b0\u1ee3ng c\u1ee7a m\u1ed9t v\u1eadt ta có th\u1ec3 suy ra tr\u1ecdng l\u01b0\u1ee3ng c\u1ee7a v\u1eadt \u0111ó."],"correct":"3","level":"2","hint":"","answer":"Nh\u1eadn xét sai là C.<\/strong> Vì P = mg nên kh\u1ed1i l\u01b0\u1ee3ng và tr\u1ecdng l\u01b0\u1ee3ng c\u1ee7a v\u1eadt không thay \u0111\u1ed5i theo v\u1ecb trí \u0111\u1eb7t v\u1eadt.<\/span><\/p>A, B \u0111úng vì: kh\u1ed1i l\u01b0\u1ee3ng ch\u1ec9 l\u01b0\u1ee3ng ch\u1ea5t t\u1ea1o nên v\u1eadt \u0111ó, không thay \u0111\u1ed5i \u1edf các v\u1ecb trí khác nhau và có tính ch\u1ea5t c\u1ed9ng.<\/p>C - sai vì: Công th\u1ee9c P = mg ch\u1ec9 là công th\u1ee9c t\u1ed5ng quát. Kh\u1ed1i l\u01b0\u1ee3ng v\u1eadt không thay \u0111\u1ed5i theo v\u1ecb trí \u0111\u1eb7t v\u1eadt nh\u01b0ng gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng g s\u1ebd thay \u0111\u1ed5i theo v\u1ecb trí \u0111\u1eb7t v\u1eadt, d\u1eabn \u0111\u1ebfn tr\u1ecdng l\u01b0\u1ee3ng s\u1ebd thay \u0111\u1ed5i.<\/p>D \u0111úng vì: n\u1ebfu bi\u1ebft kh\u1ed1i l\u01b0\u1ee3ng m c\u1ee7a v\u1eadt thì tính tr\u1ecdng l\u01b0\u01a1ng c\u1ee7a v\u1eadt b\u1eb1ng công th\u1ee9c P = mg.<\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2025-02-24 08:03:48","option_type":"txt","len":3},{"id":"7671","mon_id":"1158790","chapter_id":"1158796","post_id":"8520","question":"Bi\u1ebft kh\u1ed1i l\u01b0\u1ee3ng c\u1ee7a qu\u1ea3 táo là 200 g, r\u01a1i t\u1ef1 do xu\u1ed1ng m\u1eb7t \u0111\u1ea5t, l\u1ea5y g = 9,8 (m\/s²). Tính l\u1ef1c hút c\u1ee7a Trái \u0110\u1ea5t lên qu\u1ea3 táo.<\/p>","options":["A.<\/strong> 2 N.","B.<\/strong> 0,2 N.","C.<\/strong> 1,96 N.","D.<\/strong> 19,6 N."],"correct":"3","level":"2","hint":"","answer":"Ch\u1ecdn C.<\/strong> 1,96 N.<\/span><\/p>\u0110\u1ed5i: 200 g = 0,2 kg.<\/p>L\u1ef1c hút c\u1ee7a Trái \u0110\u1ea5t lên qu\u1ea3 táo là: P = m.g = 0,2 . 9,8 = 1,96 (N).<\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2025-02-24 08:06:34","option_type":"txt","len":0},{"id":"7672","mon_id":"1158790","chapter_id":"1158796","post_id":"8520","question":"Treo m\u1ed9t v\u1eadt vào l\u1ef1c k\u1ebf nh\u01b0 hình v\u1ebd, l\u1ef1c k\u1ebf lúc này ch\u1ec9 5 N. Hãy tính kh\u1ed1i l\u01b0\u1ee3ng c\u1ee7a v\u1eadt n\u1eb7ng. L\u1ea5y g = 10 m\/s².<\/p><svg height=\"290\" width=\"100\"> <g><title><\/title><rect fill=\"#fff\" height=\"292\" id=\"canvas_background\" width=\"102\" x=\"-1\" y=\"-1\"><\/rect> <g display=\"none\" id=\"canvasGrid\"> <rect fill=\"url(#gridpattern)\" height=\"100%\" id=\"svg_6\" stroke-width=\"0\" width=\"100%\" x=\"0\" y=\"0\"><\/rect> <\/g> <\/g> <g><title><\/title><g id=\"svg_7\"> <ellipse cx=\"34\" cy=\"266.58333\" fill=\"#ff5656\" id=\"svg_5\" rx=\"20\" ry=\"20\" stroke=\"#000\" stroke-opacity=\"null\" stroke-width=\"1.5\"><\/ellipse> <path d=\"m10.86308,213.77942c0,-2.27227 3.02423,-4.11781 6.74837,-4.11781c3.72414,0 6.75054,1.84554 6.75054,4.11781c0,-2.27227 3.02205,-4.11781 6.74837,-4.11781c3.72632,0 3.38399,0.43229 4.58976,1.11397l0,33.88465c0,1.51578 -0.9681,2.74336 -2.15861,2.74336c-1.19268,0 -2.16078,-1.22758 -2.16078,-2.74336l0,-1.37445l-4.31939,0l0,1.37445c0,4.54733 2.9043,8.2384 6.48017,8.2384s6.478,-3.69107 6.478,-8.2384l0,-33.88465c1.20576,-0.68445 2.81927,-1.11397 4.59194,-1.11397c1.77267,0 6.75054,1.84554 6.75054,4.11781c0,-2.27227 3.02423,-4.11781 6.74619,-4.11781c3.72196,0 6.75491,1.84554 6.75491,4.11781l-54.00001,0z\" fill=\"#0000ff\" id=\"svg_4\" stroke=\"#000\" stroke-opacity=\"null\" stroke-width=\"1.5\"><\/path> <rect fill=\"#aaffd4\" height=\"217.99999\" id=\"svg_1\" rx=\"10\" stroke=\"#000\" stroke-width=\"1.5\" width=\"85\" x=\"8\" y=\"4.58334\"><\/rect> <rect fill=\"#ffff56\" height=\"189.00001\" id=\"svg_2\" stroke=\"#000\" stroke-opacity=\"null\" stroke-width=\"1.5\" width=\"29\" x=\"13\" y=\"21.58333\"><\/rect> <rect fill=\"#0000ff\" height=\"12\" id=\"svg_3\" stroke=\"#000\" stroke-opacity=\"null\" stroke-width=\"1.5\" width=\"14\" x=\"30\" y=\"222.58333\"><\/rect> <line fill=\"none\" fill-opacity=\"null\" id=\"svg_9\" stroke=\"#000\" stroke-linecap=\"null\" stroke-linejoin=\"null\" stroke-opacity=\"null\" stroke-width=\"1.5\" x1=\"24\" x2=\"42\" y1=\"42.58333\" y2=\"42.58333\"><\/line> <line fill=\"none\" fill-opacity=\"null\" id=\"svg_10\" stroke=\"#000\" stroke-linecap=\"null\" stroke-linejoin=\"null\" stroke-opacity=\"null\" stroke-width=\"1.5\" x1=\"24\" x2=\"42\" y1=\"63\" y2=\"63\"><\/line> <line fill=\"none\" fill-opacity=\"null\" id=\"svg_11\" stroke=\"#000\" stroke-linecap=\"null\" stroke-linejoin=\"null\" stroke-opacity=\"null\" stroke-width=\"1.5\" x1=\"24\" x2=\"42\" y1=\"83\" y2=\"83\"><\/line> <line fill=\"none\" fill-opacity=\"null\" id=\"svg_12\" stroke=\"#000\" stroke-linecap=\"null\" stroke-linejoin=\"null\" stroke-opacity=\"null\" stroke-width=\"1.5\" x1=\"24\" x2=\"42\" y1=\"103\" y2=\"103\"><\/line> <line fill=\"none\" fill-opacity=\"null\" id=\"svg_13\" stroke=\"#000\" stroke-linecap=\"null\" stroke-linejoin=\"null\" stroke-opacity=\"null\" stroke-width=\"1.5\" x1=\"24\" x2=\"42\" y1=\"123\" y2=\"123\"><\/line> <line fill=\"none\" fill-opacity=\"null\" id=\"svg_14\" stroke=\"#000\" stroke-linecap=\"null\" stroke-linejoin=\"null\" stroke-opacity=\"null\" stroke-width=\"1.5\" x1=\"24\" x2=\"42\" y1=\"143\" y2=\"143\"><\/line> <line fill=\"none\" fill-opacity=\"null\" id=\"svg_15\" stroke=\"#000\" stroke-linecap=\"null\" stroke-linejoin=\"null\" stroke-opacity=\"null\" stroke-width=\"1.5\" x1=\"24\" x2=\"42\" y1=\"163\" y2=\"163\"><\/line> <line fill=\"none\" fill-opacity=\"null\" id=\"svg_16\" stroke=\"#000\" stroke-linecap=\"null\" stroke-linejoin=\"null\" stroke-opacity=\"null\" stroke-width=\"1.5\" x1=\"24\" x2=\"42\" y1=\"183\" y2=\"183\"><\/line> <text fill=\"#000000\" fill-opacity=\"null\" font-family=\"Helvetica, Arial, sans-serif\" font-size=\"17\" id=\"svg_17\" stroke=\"#000\" stroke-opacity=\"null\" stroke-width=\"0\" text-anchor=\"start\" x=\"48\" xml:space=\"preserve\" y=\"26.58333\">0 N<\/text> <text fill=\"#000000\" fill-opacity=\"null\" font-family=\"Helvetica, Arial, sans-serif\" font-size=\"17\" id=\"svg_18\" stroke=\"#000\" stroke-opacity=\"null\" stroke-width=\"0\" text-anchor=\"start\" x=\"47\" xml:space=\"preserve\" y=\"47\">1<\/text> <text fill=\"#000000\" fill-opacity=\"null\" font-family=\"Helvetica, Arial, sans-serif\" font-size=\"17\" id=\"svg_20\" stroke=\"#000\" stroke-opacity=\"null\" stroke-width=\"0\" text-anchor=\"start\" x=\"47\" xml:space=\"preserve\" y=\"87\">2<\/text> <text fill=\"#000000\" fill-opacity=\"null\" font-family=\"Helvetica, Arial, sans-serif\" font-size=\"17\" id=\"svg_22\" stroke=\"#000\" stroke-opacity=\"null\" stroke-width=\"0\" text-anchor=\"start\" x=\"47\" xml:space=\"preserve\" y=\"126.58333\">3<\/text> <text fill=\"#000000\" fill-opacity=\"null\" font-family=\"Helvetica, Arial, sans-serif\" font-size=\"17\" id=\"svg_24\" stroke=\"#000\" stroke-opacity=\"null\" stroke-width=\"0\" text-anchor=\"start\" x=\"47\" xml:space=\"preserve\" y=\"166.58333\">4<\/text> <text fill=\"#000000\" fill-opacity=\"null\" font-family=\"Helvetica, Arial, sans-serif\" font-size=\"17\" id=\"svg_25\" stroke=\"#000\" stroke-opacity=\"null\" stroke-width=\"0\" text-anchor=\"start\" x=\"47\" xml:space=\"preserve\" y=\"206.58333\">5<\/text> <line fill=\"none\" fill-opacity=\"null\" id=\"svg_26\" stroke=\"#000\" stroke-linecap=\"null\" stroke-linejoin=\"null\" stroke-opacity=\"null\" stroke-width=\"1.5\" x1=\"24\" x2=\"42\" y1=\"203\" y2=\"203\"><\/line> <path d=\"m10.005,209.17353l6,-11l6,11l-12,0z\" fill=\"#ff0000\" id=\"svg_27\" stroke=\"#000\" stroke-opacity=\"null\" stroke-width=\"1.5\" transform=\"rotate(90 16.004997253417944,203.67352294921878) \"><\/path> <\/g> <\/g> <\/svg><\/span><\/p>","options":["A.<\/strong> 250 g.","B.<\/strong> 500 g.","C.<\/strong> 1 kg.","D.<\/strong> 2 kg."],"correct":"2","level":"2","hint":"V\u1eadt \u1edf tr\u1ea1ng thái cân b\u1eb1ng: $F_{\u0111h}$<\/span>= P.<\/p>","answer":"Ch\u1ecdn B.<\/strong> 500 g.<\/span><\/p>Khi v\u1eadt n\u1eb7ng \u1edf tr\u1ea1ng thái cân b\u1eb1ng, v\u1eadt ch\u1ecbu tác d\u1ee5ng c\u1ee7a hai l\u1ef1c cân b\u1eb1ng là l\u1ef1c \u0111àn h\u1ed3i $\\overrightarrow{F_{\u0111h}}$<\/span> và tr\u1ecdng l\u1ef1c $\\overrightarrow{P}$<\/span>.<\/p>Do \u0111ó, ta có: $F_{\u0111h}=P=5$<\/span> (N).<\/p>Suy ra mg = 5 ⇔ m . 10 = 5 ⇔ m = 0,5 (kg) = 500 (g).<\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2025-02-24 08:10:25","option_type":"txt","len":0}]}