{"id":9131,"date":"2023-08-16T15:16:19","date_gmt":"2023-08-16T15:16:19","guid":{"rendered":"http:\/\/dialtous.com\/?p=9131"},"modified":"2023-08-16T15:16:19","modified_gmt":"2023-08-16T15:16:19","slug":"ti-xich-trong-vat-ly-la-gi","status":"publish","type":"post","link":"https:\/\/dialtous.com\/ti-xich-trong-vat-ly-la-gi\/","title":{"rendered":"B\u00e0i 4: Bi\u1ec3u di\u1ec5n l\u1ef1c"},"content":{"rendered":"<p><img decoding=\"async\" src=\"http:\/\/dialtous.com\/images\/logo.png\" alt=\"LADEC\" \/><\/p>\n<h2>I. \u00d4n l\u1ea1i kh\u00e1i ni\u1ec7m l\u1ef1c<\/h2>\n<p>C\u00e2u C1 trang 20 VBT V\u1eadt L\u00ed 8:<br \/>\nL\u1eddi gi\u1ea3i:<br \/>\nNam ch\u00e2m h\u00fat s\u1eaft l\u00e0m cho s\u1eaft g\u1eafn v\u1edbi xe chuy\u1ec3n \u0111\u1ed9ng nhanh l\u00ean. Nh\u01b0 v\u1eady l\u1ef1c c\u00f3 t\u00e1c d\u1ee5ng l\u00e0m thay \u0111\u1ed5i v\u1eadn t\u1ed1c c\u1ee7a chuy\u1ec3n \u0111\u1ed9ng (nhanh d\u1ea7n v\u1ec1 ph\u00eda nam ch\u00e2m).<\/p>\n<ul>\n<li>Qu\u1ea3 b\u00f3ng \u0111\u1eadp v\u00e0o v\u1ee3t l\u00e0m b\u00f3ng v\u00e0 v\u1ee3t c\u00f9ng b\u1ecb bi\u1ebfn d\u1ea1ng. Nh\u01b0 v\u1eady l\u1ef1c c\u00f3 t\u00e1c d\u1ee5ng l\u00e0m v\u1eadt b\u1ecb bi\u1ebfn d\u1ea1ng.<\/li>\n<\/ul>\n<p>K\u1ebft lu\u1eadn: L\u1ef1c c\u00f3 th\u1ec3 l\u00e0m bi\u1ebfn d\u1ea1ng, thay \u0111\u1ed5i chuy\u1ec3n \u0111\u1ed9ng c\u1ee7a v\u1eadt.<\/p>\n<h2>II. Bi\u1ec3u di\u1ec5n l\u1ef1c<\/h2>\n<ol>\n<li>L\u1ef1c l\u00e0 m\u1ed9t \u0111\u1ea1i l\u01b0\u1ee3ng vect\u01a1<br \/>\n\u0110\u1eb7c \u0111i\u1ec3m c\u1ee7a \u0111\u1ea1i l\u01b0\u1ee3ng vect\u01a1 g\u1ed3m:<\/li>\n<\/ol>\n<ul>\n<li>Ph\u01b0\u01a1ng, chi\u1ec1u tr\u00f9ng v\u1edbi ph\u01b0\u01a1ng, chi\u1ec1u c\u1ee7a l\u1ef1c.<\/li>\n<li>\u0110\u1ed9 d\u00e0i bi\u1ec3u th\u1ecb \u0111\u1ed9 l\u1edbn c\u1ee7a vect\u01a1.<\/li>\n<\/ul>\n<ol start=\"2\">\n<li>T\u00f3m t\u1eaft c\u00e1ch bi\u1ec3u di\u1ec5n vect\u01a1 l\u1ef1c F\u2192<br \/>\nL\u1ef1c l\u00e0 m\u1ed9t \u0111\u1ea1i l\u01b0\u1ee3ng vect\u01a1 \u0111\u01b0\u1ee3c bi\u1ec3u di\u1ec5n b\u1eb1ng m\u1ed9t m\u0169i t\u00ean c\u00f3:<\/li>\n<\/ol>\n<ul>\n<li>G\u1ed1c l\u00e0 \u0111i\u1ec3m \u0111\u1eb7t c\u1ee7a l\u1ef1c.<\/li>\n<li>Ph\u01b0\u01a1ng, chi\u1ec1u tr\u00f9ng v\u1edbi ph\u01b0\u01a1ng, chi\u1ec1u c\u1ee7a l\u1ef1c.<\/li>\n<li>\u0110\u1ed9 d\u00e0i bi\u1ec3u th\u1ecb c\u01b0\u1eddng \u0111\u1ed9 c\u1ee7a l\u1ef1c theo t\u1ec9 x\u00edch cho tr\u01b0\u1edbc.<\/li>\n<li>K\u00ed hi\u1ec7u c\u1ee7a vect\u01a1 l\u1ef1c: F\u2192<\/li>\n<li>K\u00ed hi\u1ec7u c\u1ee7a c\u01b0\u1eddng \u0111\u1ed9 l\u1ef1c: F.<\/li>\n<\/ul>\n<h2>III. V\u1eadn d\u1ee5ng<\/h2>\n<p>C\u00e2u C2 trang 20-21 VBT V\u1eadt L\u00ed 8:<br \/>\nL\u1eddi gi\u1ea3i:<br \/>\nBi\u1ec3u di\u1ec5n nh\u1eefng l\u1ef1c sau \u0111\u00e2y b\u1eb1ng vect\u01a1 l\u1ef1c:<\/p>\n<ul>\n<li>Tr\u1ecdng l\u1ef1c c\u1ee7a m\u1ed9t v\u1eadt c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 5kg (t\u1ec9 x\u00edch 0,5 cm \u1ee9ng v\u1edbi 10N).<\/li>\n<\/ul>\n<p>C3 trang 21 VBT V\u1eadt L\u00ed 8: Di\u1ec5n t\u1ea3 b\u1eb1ng l\u1eddi c\u00e1c y\u1ebfu t\u1ed1 c\u1ee7a c\u00e1c l\u1ef1c v\u1ebd \u1edf h\u00ecnh 4.4 SGK:<br \/>\nL\u1eddi gi\u1ea3i:<br \/>\nL\u1ef1c F1\u2192: Ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng, chi\u1ec1u t\u1eeb d\u01b0\u1edbi l\u00ean tr\u00ean, \u0111\u1ed9 l\u1edbn 20N.<br \/>\nL\u1ef1c F2\u2192: Ph\u01b0\u01a1ng n\u1eb1m ngang, chi\u1ec1u t\u1eeb tr\u00e1i sang ph\u1ea3i, \u0111\u1ed9 l\u1edbn 30N.<br \/>\nL\u1ef1c F3\u2192: Ph\u01b0\u01a1ng h\u1ee3p v\u1edbi ph\u01b0\u01a1ng n\u1eb1m ngang m\u1ed9t g\u00f3c 30o, chi\u1ec1u xi\u00ean l\u00ean t\u1eeb tr\u00e1i sang ph\u1ea3i, \u0111\u1ed9 l\u1edbn 30N.<\/p>\n<p>Ghi nh\u1edb:<br \/>\nL\u1ef1c l\u00e0 m\u1ed9t \u0111\u1ea1i l\u01b0\u1ee3ng vect\u01a1 \u0111\u01b0\u1ee3c bi\u1ec3u di\u1ec5n b\u1eb1ng m\u1ed9t m\u0169i t\u00ean c\u00f3:<\/p>\n<ul>\n<li>G\u1ed1c l\u00e0 \u0111i\u1ec3m \u0111\u1eb7t c\u1ee7a l\u1ef1c.<\/li>\n<li>Ph\u01b0\u01a1ng, chi\u1ec1u tr\u00f9ng v\u1edbi ph\u01b0\u01a1ng, chi\u1ec1u c\u1ee7a l\u1ef1c.<\/li>\n<li>\u0110\u1ed9 d\u00e0i bi\u1ec3u th\u1ecb c\u01b0\u1eddng \u0111\u1ed9 c\u1ee7a l\u1ef1c theo t\u1ec9 x\u00edch cho tr\u01b0\u1edbc.<\/li>\n<\/ul>\n<h2>B\u00e0i t\u1eadp<\/h2>\n<p>B\u00e0i 4.1 trang 22 VBT V\u1eadt L\u00ed 8:<br \/>\nKhi ch\u1ec9 c\u00f3 m\u1ed9t l\u1ef1c t\u00e1c d\u1ee5ng l\u00ean v\u1eadt th\u00ec v\u1eadn t\u1ed1c c\u1ee7a v\u1eadt s\u1ebd nh\u01b0 th\u1ebf n\u00e0o? H\u00e3y ch\u1ecdn c\u00e2u tr\u1ea3 l\u1eddi \u0111\u00fang nh\u1ea5t.<br \/>\nA. V\u1eadn t\u1ed1c kh\u00f4ng thay \u0111\u1ed5i.<br \/>\nB. V\u1eadn t\u1ed1c t\u0103ng d\u1ea7n.<br \/>\nC. V\u1eadn t\u1ed1c gi\u1ea3m d\u1ea7n.<br \/>\nD. C\u00f3 th\u1ec3 t\u0103ng d\u1ea7n v\u00e0 c\u0169ng c\u00f3 th\u1ec3 gi\u1ea3m d\u1ea7n.<br \/>\nL\u1eddi gi\u1ea3i:<br \/>\nCh\u1ecdn D.<br \/>\nN\u1ebfu l\u1ef1c t\u00e1c d\u1ee5ng l\u00ean v\u1eadt l\u00e0 l\u1ef1c k\u00e9o th\u00ec s\u1ebd l\u00e0m cho v\u1eadn t\u1ed1c c\u1ee7a v\u1eadt t\u0103ng d\u1ea7n, nh\u01b0ng n\u1ebfu l\u00e0 l\u1ef1c c\u1ea3n th\u00ec s\u1ebd l\u00e0m cho v\u1eadn t\u1ed1c c\u1ee7a v\u1eadt gi\u1ea3m d\u1ea7n.<\/p>\n<p>B\u00e0i 4.2 trang 22 VBT V\u1eadt L\u00ed 8:<br \/>\nL\u1eddi gi\u1ea3i:<br \/>\nV\u00ed d\u1ee5 v\u1ec1 l\u1ef1c l\u00e0m t\u0103ng v\u1eadn t\u1ed1c: M\u1ed9t chi\u1ebfc xe \u0111ang \u0111\u1ed5 d\u1ed1c, n\u1ebfu kh\u00f4ng c\u00f3 l\u1ef1c h\u00e3m th\u00ec l\u1ef1c h\u00fat c\u1ee7a Tr\u00e1i \u0110\u1ea5t s\u1ebd l\u00e0m t\u0103ng v\u1eadn t\u1ed1c c\u1ee7a xe.<\/p>\n<p>V\u00ed d\u1ee5 v\u1ec1 l\u1ef1c l\u00e0m gi\u1ea3m v\u1eadn t\u1ed1c: Xe \u0111ang chuy\u1ec3n \u0111\u1ed9ng tr\u00ean \u0111o\u1ea1n \u0111\u01b0\u1eddng ngang, n\u1ebfu kh\u00f4ng c\u00f3 l\u1ef1c t\u00e1c \u0111\u1ed9ng n\u1eefa, l\u1ef1c c\u1ea3n c\u1ee7a kh\u00f4ng kh\u00ed s\u1ebd l\u00e0m gi\u1ea3m t\u1ed1c \u0111\u1ed9 xe.<\/p>\n<p>B\u00e0i 4.3 trang 22 VBT V\u1eadt L\u00ed 8:<br \/>\nL\u1eddi gi\u1ea3i:<br \/>\nKhi th\u1ea3 v\u1eadt r\u01a1i, do s\u1ee9c h\u00fat c\u1ee7a Tr\u00e1i \u0110\u1ea5t, v\u1eadn t\u1ed1c c\u1ee7a v\u1eadt t\u0103ng.<\/p>\n<p>Khi qu\u1ea3 b\u00f3ng l\u0103n v\u00e0o b\u00e3i c\u00e1t, do l\u1ef1c c\u1ea3n c\u1ee7a c\u00e1t n\u00ean v\u1eadn t\u1ed1c c\u1ee7a b\u00f3ng b\u1ecb gi\u1ea3m.<\/p>\n<p>B\u00e0i 4.4 trang 22-23 VBT V\u1eadt L\u00ed 8:<br \/>\nL\u1eddi gi\u1ea3i:<br \/>\na)<br \/>\nV\u1eadt ch\u1ecbu t\u00e1c d\u1ee5ng c\u1ee7a hai l\u1ef1c: l\u1ef1c k\u00e9o Fk c\u00f3 ph\u01b0\u01a1ng n\u1eb1m ngang, chi\u1ec1u t\u1eeb tr\u00e1i sang ph\u1ea3i, \u0111\u1ed9 l\u1edbn 250N. L\u1ef1c c\u1ea3n Fc c\u00f3 ph\u01b0\u01a1ng n\u1eb1m ngang, chi\u1ec1u t\u1eeb ph\u1ea3i sang tr\u00e1i, \u0111\u1ed9 l\u1edbn 150N.<\/p>\n<p>b)<br \/>\nV\u1eadt ch\u1ecbu t\u00e1c d\u1ee5ng c\u1ee7a hai l\u1ef1c: tr\u1ecdng l\u1ef1c P c\u00f3 ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng, chi\u1ec1u t\u1eeb tr\u00ean xu\u1ed1ng d\u01b0\u1edbi, \u0111\u1ed9 l\u1edbn 200N. L\u1ef1c k\u00e9o Fk nghi\u00eang m\u1ed9t g\u00f3c 30o v\u1edbi ph\u01b0\u01a1ng n\u1eb1m ngang, chi\u1ec1u h\u01b0\u1edbng l\u00ean tr\u00ean, \u0111\u1ed9 l\u1edbn 300N.<\/p>\n<p>B\u00e0i 4.5 trang 23 VBT V\u1eadt L\u00ed 8:<br \/>\nL\u1eddi gi\u1ea3i:<br \/>\na) Tr\u1ecdng l\u1ef1c c\u1ee7a m\u1ed9t v\u1eadt l\u00e0 1500N (t\u1ec9 l\u1ec7 x\u00edch t\u00f9y ch\u1ecdn).<\/p>\n<ul>\n<li>L\u1ef1c k\u00e9o c\u1ee7a m\u1ed9t x\u00e0 lan l\u00e0 2000N theo ph\u01b0\u01a1ng ngang, chi\u1ec1u t\u1eeb tr\u00e1i sang ph\u1ea3i, t\u1ec9 x\u00edch \u1ee9ng v\u1edbi 500N.<\/li>\n<\/ul>\n<p>B\u00e0i 4a trang 23-24 VBT V\u1eadt L\u00ed 8:<br \/>\nM\u1ed9t b\u00f3ng \u0111\u00e8n c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 1kg \u0111\u01b0\u1ee3c treo b\u1edfi hai s\u1ee3i d\u00e2y g\u1eafn v\u00e0o hai b\u1edd t\u01b0\u1eddng. Bi\u1ebft s\u1ee9c c\u0103ng c\u1ee7a m\u1ed7i s\u1ee3i d\u00e2y b\u1eb1ng 10N, g\u00f3c h\u1ee3p b\u1edfi ph\u01b0\u01a1ng c\u1ee7a hai s\u1ee3i d\u00e2y b\u1eb1ng 120o (H.4.1). H\u00e3y bi\u1ec3u di\u1ec5n c\u00e1c l\u1ef1c t\u00e1c d\u1ee5ng \u0111\u00e8n. Ch\u1ecdn t\u1ec9 x\u00edch 10N \u1ee9ng v\u1edbi 1cm.<br \/>\nL\u1eddi gi\u1ea3i:<br \/>\n\u0110\u00e8n ch\u1ecbu t\u00e1c d\u1ee5ng c\u1ee7a 3 l\u1ef1c:<\/p>\n<ul>\n<li>L\u1ef1c T1: G\u1ed1c l\u00e0 \u0111i\u1ec3m O, ph\u01b0\u01a1ng n\u1eb1m tr\u00f9ng v\u1edbi s\u1ee3i d\u00e2y OA, chi\u1ec1u t\u1eeb O \u0111\u1ebfn A v\u00e0 c\u00f3 \u0111\u1ed9 l\u1edbn 10N.<\/li>\n<li>L\u1ef1c T2: G\u1ed1c l\u00e0 \u0111i\u1ec3m O, ph\u01b0\u01a1ng t\u1ea1o v\u1edbi l\u1ef1c T1 g\u00f3c 120o tr\u00f9ng v\u1edbi s\u1ee3i d\u00e2y OB, chi\u1ec1u t\u1eeb O \u0111\u1ebfn B v\u00e0 c\u00f3 \u0111\u1ed9 l\u1edbn 10N.<\/li>\n<li>Tr\u1ecdng l\u1ef1c P: G\u1ed1c l\u00e0 \u0111i\u1ec3m O, ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng, chi\u1ec1u t\u1eeb tr\u00ean xu\u1ed1ng d\u01b0\u1edbi v\u00e0 c\u00f3 \u0111\u1ed9 l\u1edbn P = 10.m = 10.1 = 10N.<\/li>\n<\/ul>\n<p>B\u00e0i 4b trang 24 VBT V\u1eadt L\u00ed 8:<br \/>\nM\u1ed9t v\u1eadt c\u00f3 tr\u1ecdng l\u01b0\u1ee3ng b\u1eb1ng 30N \u0111\u1eb7t tr\u00ean m\u1ed9t m\u1eb7t n\u1eb1m ngang. L\u1ef1c k\u00e9o v\u1eadt theo ph\u01b0\u01a1ng n\u1eb1m ngang c\u00f3 c\u01b0\u1eddng \u0111\u1ed9 b\u1eb1ng 40N. L\u1ef1c c\u1ea3n l\u00ean v\u1eadt c\u00f3 c\u01b0\u1eddng \u0111\u1ed9 b\u1eb1ng n\u1eeda c\u01b0\u1eddng \u0111\u1ed9 l\u1ef1c k\u00e9o. H\u00e3y bi\u1ec3u di\u1ec5n c\u00e1c l\u1ef1c t\u00e1c d\u1ee5ng l\u00ean v\u1eadt b\u1eb1ng vect\u01a1. Ch\u1ecdn t\u1ec9 x\u00edch 10N \u1ee9ng v\u1edbi 1cm.<br \/>\nL\u1eddi gi\u1ea3i:<br \/>\nV\u1eadt ch\u1ecbu t\u00e1c d\u1ee5ng c\u1ee7a 3 l\u1ef1c:<\/p>\n<ul>\n<li>L\u1ef1c k\u00e9o Fk: G\u1ed1c l\u00e0 \u0111i\u1ec3m O, ph\u01b0\u01a1ng n\u1eb1m ngang, chi\u1ec1u sang ph\u1ea3i v\u00e0 c\u00f3 \u0111\u1ed9 l\u1edbn 40N.<\/li>\n<li>L\u1ef1c c\u1ea3n Fc: G\u1ed1c l\u00e0 \u0111i\u1ec3m O, ph\u01b0\u01a1ng n\u1eb1m ngang, chi\u1ec1u sang tr\u00e1i v\u00e0 c\u00f3 \u0111\u1ed9 l\u1edbn 20N.<\/li>\n<li>Tr\u1ecdng l\u1ef1c P: G\u1ed1c l\u00e0 \u0111i\u1ec3m O, ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng, chi\u1ec1u t\u1eeb tr\u00ean xu\u1ed1ng d\u01b0\u1edbi v\u00e0 c\u00f3 \u0111\u1ed9 l\u1edbn P = 30N.<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>I. \u00d4n l\u1ea1i kh\u00e1i ni\u1ec7m l\u1ef1c C\u00e2u C1 trang 20 VBT V\u1eadt L\u00ed 8: L\u1eddi gi\u1ea3i: Nam ch\u00e2m h\u00fat s\u1eaft l\u00e0m cho s\u1eaft g\u1eafn v\u1edbi xe chuy\u1ec3n \u0111\u1ed9ng nhanh l\u00ean. Nh\u01b0 v\u1eady l\u1ef1c c\u00f3 t\u00e1c d\u1ee5ng l\u00e0m thay \u0111\u1ed5i v\u1eadn t\u1ed1c c\u1ee7a chuy\u1ec3n \u0111\u1ed9ng (nhanh d\u1ea7n v\u1ec1 ph\u00eda nam ch\u00e2m). Qu\u1ea3 b\u00f3ng \u0111\u1eadp v\u00e0o v\u1ee3t [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[22],"tags":[],"class_list":["post-9131","post","type-post","status-publish","format-standard","hentry","category-hoi-dap"],"_links":{"self":[{"href":"https:\/\/dialtous.com\/wp-json\/wp\/v2\/posts\/9131"}],"collection":[{"href":"https:\/\/dialtous.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/dialtous.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/dialtous.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/dialtous.com\/wp-json\/wp\/v2\/comments?post=9131"}],"version-history":[{"count":1,"href":"https:\/\/dialtous.com\/wp-json\/wp\/v2\/posts\/9131\/revisions"}],"predecessor-version":[{"id":9134,"href":"https:\/\/dialtous.com\/wp-json\/wp\/v2\/posts\/9131\/revisions\/9134"}],"wp:attachment":[{"href":"https:\/\/dialtous.com\/wp-json\/wp\/v2\/media?parent=9131"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/dialtous.com\/wp-json\/wp\/v2\/categories?post=9131"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/dialtous.com\/wp-json\/wp\/v2\/tags?post=9131"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}