{"id":3430,"date":"2021-10-20T17:10:38","date_gmt":"2021-10-20T10:10:38","guid":{"rendered":"https:\/\/www.vietlearn.org\/post\/?p=3430"},"modified":"2021-10-22T18:08:39","modified_gmt":"2021-10-22T11:08:39","slug":"van-toc-la-gi-cong-thuc-tinh-van-toc-quang-duong-va-thoi-gian","status":"publish","type":"post","link":"https:\/\/www.vietlearn.org\/kien-thuc\/van-toc-la-gi-cong-thuc-tinh-van-toc-quang-duong-va-thoi-gian\/","title":{"rendered":"V\u1eadn t\u1ed1c l\u00e0 g\u00ec, c\u00f4ng th\u1ee9c t\u00ednh v\u1eadn t\u1ed1c, qu\u00e3ng \u0111\u01b0\u1eddng v\u00e0 th\u1eddi gian"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">Ghi ch\u00fa: T\u00e0i li\u1ec7u tr\u00edch d\u1eabn<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">V\u1eadn t\u1ed1c l\u00e0 m\u1ed9t \u0111\u1ea1i l\u01b0\u1ee3ng v\u1eadt l\u00fd m\u00f4 t\u1ea3 m\u1ee9c \u0111\u1ed9 nhanh hay ch\u1eadm c\u1ee7a chuy\u1ec3n \u0111\u1ed9ng, \u0111\u00e2y tr\u1edf th\u00e0nh ch\u01b0\u01a1ng tr\u00ecnh h\u1ecdc quan tr\u1ecdng c\u1ee7a V\u1eadt l\u00fd 8. Tuy nhi\u00ean, kh\u00f4ng ph\u1ea3i ai c\u0169ng gi\u1ea3i th\u00edch \u0111\u01b0\u1ee3c kh\u00e1i ni\u1ec7m v\u1eadn t\u1ed1c l\u00e0 g\u00ec? C\u00f4ng th\u1ee9c t\u00ednh nh\u01b0 th\u1ebf n\u00e0o? V\u1eady th\u00ec \u0111\u1eebng b\u1ecf l\u1ee1 b\u1ea5t k\u1ef3 n\u1ed9i dung th\u00f4ng tin n\u00e0o trong b\u00e0i vi\u1ebft d\u01b0\u1edbi \u0111\u00e2y c\u1ee7a ch\u00fang t\u00f4i.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">V\u1eadn t\u1ed1c l\u00e0 \u0111\u1ea1i l\u01b0\u1ee3ng m\u00f4 t\u1ea3 m\u1ee9c \u0111\u1ed9 nhanh ch\u1eadm v\u00e0 chi\u1ec1u c\u1ee7a chuy\u1ec3n \u0111\u1ed9ng. V\u1eadn t\u1ed1c \u0111\u01b0\u1ee3c x\u00e1c \u0111\u1ecbnh d\u1ef1a tr\u00ean \u0111\u01b0\u1eddng \u0111i \u0111\u01b0\u1ee3c trong m\u1ed9t \u0111\u01a1n v\u1ecb th\u1eddi gian. V\u1eadn t\u1ed1c \u0111\u01b0\u1ee3c bi\u1ec3u di\u1ec5n b\u1edfi vect\u01a1, \u0111\u1ed9 d\u00e0i c\u1ee7a vect\u01a1 v\u1eadn t\u1ed1c cho bi\u1ebft t\u1ed1c \u0111\u1ed9 nhanh hay ch\u1eadm c\u1ee7a chuy\u1ec3n \u0111\u1ed9ng, chi\u1ec1u c\u1ee7a vect\u01a1 hi\u1ec3n th\u1ecb chi\u1ec1u c\u1ee7a chuy\u1ec3n \u0111\u1ed9ng.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">T\u1ef1u chung, v\u1eadn t\u1ed1c l\u00e0 \u0111\u1ea1i l\u01b0\u1ee3ng h\u1eefu h\u01b0\u1edbng, ph\u00e2n bi\u1ec7t v\u1edbi t\u1ed1c \u0111\u1ed9- m\u1ed9t \u0111\u1ea1i l\u01b0\u1ee3ng v\u00f4 h\u01b0\u1edbng \u0111\u01a1n thu\u1ea7n, m\u00f4 t\u1ea3 t\u00ednh nhanh hay ch\u1eadm c\u1ee7a chuy\u1ec3n \u0111\u1ed9ng. T\u1ed1c \u0111\u1ed9 l\u00e0 \u0111\u1ed9 l\u1edbn c\u1ee7a vect\u01a1 v\u1eadn t\u1ed1c.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Hi\u1ec3u m\u1ed9t c\u00e1ch ng\u1eafn g\u1ecdn, kh\u00e1i ni\u1ec7m v\u1eadn t\u1ed1c l\u00e0 qu\u00e3ng \u0111\u01b0\u1eddng v\u1eadt di chuy\u1ec3n \u0111\u01b0\u1ee3c trong 1 gi\u00e2y. \u0110\u1ed9 l\u1edbn c\u1ee7a v\u1eadn t\u1ed1c cho bi\u1ebft m\u1ee9c \u0111\u1ed9 nhanh, ch\u1eadm c\u1ee7a chuy\u1ec3n \u0111\u1ed9ng v\u00e0 \u0111\u01b0\u1ee3c t\u00ednh b\u1eb1ng \u0111\u1ed9 d\u00e0i qu\u00e3ng \u0111\u01b0\u1eddng \u0111i \u0111\u01b0\u1ee3c trong m\u1ed9t \u0111\u01a1n v\u1ecb th\u1eddi gian.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">C\u00f4ng th\u1ee9c t\u00ednh v\u1eadn t\u1ed1c, th\u1eddi gian, qu\u00e3ng \u0111\u01b0\u1eddng<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">V\u1eadn t\u1ed1c trong chuy\u1ec3n \u0111\u1ed9ng th\u1eb3ng \u0111\u1ec1u \u0111\u01b0\u1ee3c t\u00ednh b\u1eb1ng c\u00f4ng th\u1ee9c: v= s\/t<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Trong \u0111\u00f3:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">v: l\u00e0 v\u1eadn t\u1ed1c<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">s: l\u00e0 qu\u00e3ng \u0111\u01b0\u1eddng v\u1eadt \u0111i \u0111\u01b0\u1ee3c<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">t: th\u1eddi gian \u0111i h\u1ebft qu\u00e3ng \u0111\u01b0\u1eddng.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">T\u1eeb c\u00f4ng th\u1ee9c t\u00ednh v\u1eadn t\u1ed1c, b\u1ea1n c\u00f3 th\u1ec3 t\u00ednh \u0111\u01b0\u1ee3c 2 \u0111\u1ea1i l\u01b0\u1ee3ng qu\u00e3ng \u0111\u01b0\u1eddng, th\u1eddi gian.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">C\u00f4ng th\u1ee9c t\u00ednh qu\u00e3ng \u0111\u01b0\u1eddng khi bi\u1ebft \u0111\u01b0\u1ee3c v\u1eadn t\u1ed1c v\u00e0 th\u1eddi gian: s= v*t<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">C\u00f4ng th\u1ee9c t\u00ednh th\u1eddi gian khi bi\u1ebft v\u1eadn t\u1ed1c v\u00e0 qu\u00e3ng \u0111\u01b0\u1eddng: t=s\/v<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u0110\u01a1n v\u1ecb c\u1ee7a v\u1eadn t\u1ed1c<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u0110\u01a1n v\u1ecb c\u1ee7a v\u1eadn t\u1ed1c ph\u1ee5 thu\u1ed9c v\u00e0o \u0111\u01a1n v\u1ecb c\u1ee7a \u0111\u1ed9 d\u00e0i v\u00e0 \u0111\u01a1n v\u1ecb c\u1ee7a th\u1eddi gian.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Trong SI, qu\u00e3ng \u0111\u01b0\u1eddng \u0111\u01b0\u1ee3c \u0111o b\u1eb1ng m\u00e9t (m), th\u1eddi gian \u0111o b\u1eb1ng gi\u00e2y (s) th\u00ec \u0111\u01a1n v\u1ecb v\u1eadt l\u00fd c\u1ee7a v\u1eadn t\u1ed1c s\u1ebd l\u00e0 m\/s. Ngo\u00e0i ra, t\u1ed1c \u0111\u1ed9 c\u00f2n c\u00f3 nh\u1eefng \u0111\u01a1n v\u1ecb kh\u00e1c nh\u01b0 km\/h. Tr\u01b0\u1edbc khi gi\u1ea3i quy\u1ebft c\u00e1c b\u00e0i to\u00e1n v\u1ec1 v\u1eadn t\u1ed1c, b\u1ea1n c\u1ea7n ph\u1ea3i xem c\u00e1c \u0111\u01a1n v\u1ecb c\u1ee7a th\u1eddi gian, qu\u00e3ng \u0111\u01b0\u1eddng \u0111\u00e3 c\u00f9ng 1 \u0111\u01a1n v\u1ecb ch\u01b0a, n\u1ebfu ch\u01b0a h\u00e3y \u0111\u1ed5i \u0111\u01a1n v\u1ecb v\u1eadn t\u1ed1c tr\u01b0\u1edbc khi th\u1ef1c hi\u1ec7n t\u00ednh to\u00e1n.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">C\u00e1ch \u0111\u1ed5i \u0111\u01a1n v\u1ecb trong v\u1eadt l\u00fd t\u01b0\u01a1ng \u0111\u1ed1i \u0111\u01a1n gi\u1ea3n, \u0111\u00f3 l\u00e0:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">1m\/s= 3,6 km\/h<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">1km\/h= 0,28 m\/s<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u0110\u1ed9 l\u1edbn c\u1ee7a v\u1eadn t\u1ed1c th\u01b0\u1eddng \u0111\u01b0\u1ee3c \u0111o b\u1eb1ng t\u1ed1c k\u1ebf.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">M\u1ed9t s\u1ed1 c\u00e2u h\u1ecfi kh\u00e1c v\u1ec1 v\u1eadn t\u1ed1c<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">V\u1eadn t\u1ed1c trung b\u00ecnh l\u00e0 g\u00ec? C\u00f4ng th\u1ee9c t\u00ednh<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">V\u1eadn t\u1ed1c trung b\u00ecnh trong m\u1ed9t kho\u1ea3ng th\u1eddi gian nh\u1ea5t \u0111\u1ecbnh \u0111\u01b0\u1ee3c \u0111\u1ecbnh ngh\u0129a l\u00e0 t\u1ef7 s\u1ed1 gi\u1eefa s\u1ef1 thay \u0111\u1ed5i v\u1ecb tr\u00ed trong kho\u1ea3ng th\u1eddi gian \u0111ang x\u00e9t v\u00e0 kho\u1ea3ng th\u1eddi gian \u0111\u00f3. Ph\u01b0\u01a1ng tr\u00ecnh to\u00e1n h\u1ecdc s\u1ebd l\u00e0:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Trong \u0111\u00f3:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">V\u1eadn t\u1ed1c trung b\u00ecnh tr\u00ean nh\u1eefng kho\u1ea3ng th\u1eddi gian kh\u00e1c nhau s\u1ebd mang c\u00e1c gi\u00e1 tr\u1ecb kh\u00e1c nhau. Th\u00eam n\u1eefa, c\u1ea7n ph\u1ea3i ph\u00e2n bi\u1ec7t v\u1edbi t\u1ed1c \u0111\u1ed9 trung b\u00ecnh \u0111\u01b0\u1ee3c \u0111\u1ecbnh ngh\u0129a l\u00e0 t\u1ed5ng qu\u00e3ng \u0111\u01b0\u1eddng \u0111i \u0111\u01b0\u1ee3c chia cho kho\u1ea3ng th\u1eddi gian x\u00e9t \u0111\u01b0\u1ee3c:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Trong \u0111\u00f3:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">v l\u00e0 v\u1eadn t\u1ed1c trung b\u00ecnh<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">s l\u00e0 t\u1ed5ng qu\u00e3ng \u0111\u01b0\u1eddng \u0111i \u0111\u01b0\u1ee3c trong kho\u1ea3ng th\u1eddi gian \u0111\u01b0\u1ee3c x\u00e9t<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">t l\u00e0 kho\u1ea3ng th\u1eddi gian \u0111\u01b0\u1ee3c x\u00e9t<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">s1,s2,\u2026sn l\u00e0 nh\u1eefng qu\u00e3ng \u0111\u01b0\u1eddng th\u00e0nh ph\u1ea7n \u0111i \u0111\u01b0\u1ee3c trong kho\u1ea3ng th\u1eddi gian th\u00e0nh ph\u1ea7n t1, t2,\u2026tn<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">V\u1eadn t\u1ed1c g\u00f3c<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">V\u1eadn t\u1ed1c g\u00f3c c\u1ee7a chuy\u1ec3n \u0111\u1ed9ng quay c\u1ee7a v\u1eadt th\u1ec3 l\u00e0 \u0111\u1ea1i l\u01b0\u1ee3ng vect\u01a1 th\u1ec3 hi\u1ec7n m\u1ee9c \u0111\u1ed9 thay \u0111\u1ed5i theo th\u1eddi gian v\u1ecb tr\u00ed g\u00f3c c\u1ee7a v\u1eadt v\u00e0 h\u01b0\u1edbng c\u1ee7a s\u1ef1 chuy\u1ec3n \u0111\u1ed9ng n\u00e0y. \u0110\u1ed9 l\u1edbn c\u1ee7a v\u1eadn t\u1ed1c g\u00f3c s\u1ebd b\u1eb1ng t\u1ed1c \u0111\u1ed9 g\u00f3c v\u00e0 h\u01b0\u1edbng c\u1ee7a vect\u01a1 v\u1eadn t\u1ed1c g\u00f3c, \u0111\u01b0\u1ee3c x\u00e1c \u0111\u1ecbnh theo quy \u01b0\u1edbc. V\u00ed d\u1ee5 nh\u01b0 quy t\u1eafc b\u00e0n tay ph\u1ea3i.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">V\u1eadn t\u1ed1c g\u00f3c \u0111\u01b0\u1ee3c t\u00ednh b\u1eb1ng c\u00f4ng th\u1ee9c \u03c9=d\u03b8\/dt v\u00e0 vector v\u1eadn t\u1ed1c g\u00f3c k\u00fd hi\u1ec7u l\u00e0 \u03c9<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">V\u1eadn t\u1ed1c t\u1ee9c th\u1eddi<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">V\u1eadn t\u1ed1c th\u1ee9c th\u1eddi m\u00f4 t\u1ea3 s\u1ef1 nhanh\/ch\u1eadm v\u00e0 chi\u1ec1u chuy\u1ec3n \u0111\u1ed9ng t\u1ea1i m\u1ed9t th\u1eddi \u0111i\u1ec3m n\u00e0o \u0111\u00f3 tr\u00ean \u0111\u01b0\u1eddng \u0111i c\u1ee7a v\u1eadt. N\u1ebfu v\u1eadn t\u1ed1c trung b\u00ecnh cho ra c\u00e1i nh\u00ecn t\u1ed5ng qu\u00e1t v\u1ec1 v\u1eadn t\u1ed1c c\u1ee7a v\u1eadt trong kho\u1ea3ng th\u1eddi gian x\u00e1c \u0111\u1ecbnh th\u00ec v\u1eadn t\u1ed1c t\u1ee9c th\u1eddi cho b\u1ea1n m\u1ed9t c\u00e1i nh\u00ecn c\u1ee5 th\u1ec3 t\u1ea1i m\u1ed9t th\u1eddi \u0111i\u1ec3m.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u0110\u1ec3 t\u00ednh v\u1eadn t\u1ed1c t\u1ee9c th\u1eddi t\u1ea1i m\u1ed9t th\u1eddi \u0111i\u1ec3m ta x\u00e9t v\u1eadn t\u1ed1c trung b\u00ecnh trong kho\u1ea3ng th\u1eddi gian v\u00f4 c\u00f9ng nh\u1ecf t\u00ednh t\u1eeb th\u1eddi \u0111i\u1ec3m \u0111\u00f3. Kh\u00e1i ni\u1ec7m gi\u1edbi h\u1ea1n trong t\u00ednh to\u00e1n gi\u1ea3i t\u00edch l\u00e0 c\u00f4ng c\u1ee5 qu\u00fd gi\u00e1 gi\u00fap b\u1ea1n l\u00e0m \u0111\u01b0\u1ee3c \u0111i\u1ec1u n\u00e0<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Ph\u01b0\u01a1ng tr\u00ecnh to\u00e1n h\u1ecdc tr\u00ean cho bi\u1ebft khi kho\u1ea3ng th\u1eddi gian \u0111\u01b0\u1ee3c x\u00e9t ti\u1ebfn d\u1ea7n \u0111\u1ebfn 0 th\u00ec v\u1eadn t\u1ed1c trung b\u00ecnh ti\u1ebfn d\u1ea7n \u0111\u1ebfn v\u1eadn t\u1ed1c t\u1ee9c th\u1eddi t\u1ea1i \u0111i\u1ec3m t0. Gi\u1edbi h\u1ea1n n\u00e0y \u0111\u1ed3ng ngh\u0129a v\u1edbi \u0111\u1ea1o h\u00e0m c\u1ee7a v\u1ecb tr\u00ed theo th\u1eddi gian. V\u1eadn t\u1ed1c t\u1ee9c th\u1eddi s\u1ebd \u0111\u01b0\u1ee3c \u0111\u1ecbnh ngh\u0129a nh\u01b0 sau:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Trong \u0111\u00f3:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Tr\u00ean \u0111\u00e2y l\u00e0 nh\u1eefng th\u00f4ng tin v\u1ec1 kh\u00e1i ni\u1ec7m v\u1eadn t\u1ed1c l\u00e0 g\u00ec? C\u00f4ng th\u1ee9c t\u00ednh, hy v\u1ecdng s\u1ebd gi\u00fap \u00edch b\u1ea1n. N\u1ebfu th\u1ea5y b\u00e0i vi\u1ebft n\u00e0y h\u1eefu \u00edch h\u00e3y like, share \u0111\u1ec3 b\u1ea1n b\u00e8 b\u1ea1n \u0111\u01b0\u1ee3c bi\u1ebft v\u00e0 s\u1eed d\u1ee5ng khi c\u1ea7n nh\u00e9.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n\n\n\n\n\n\n","protected":false},"excerpt":{"rendered":"<p>Ghi ch\u00fa: T\u00e0i li\u1ec7u tr\u00edch d\u1eabn V\u1eadn t\u1ed1c l\u00e0 m\u1ed9t \u0111\u1ea1i l\u01b0\u1ee3ng v\u1eadt l\u00fd m\u00f4 t\u1ea3 m\u1ee9c \u0111\u1ed9 nhanh hay ch\u1eadm c\u1ee7a chuy\u1ec3n \u0111\u1ed9ng, \u0111\u00e2y tr\u1edf th\u00e0nh ch\u01b0\u01a1ng tr\u00ecnh h\u1ecdc quan tr\u1ecdng c\u1ee7a V\u1eadt l\u00fd 8. Tuy nhi\u00ean, kh\u00f4ng ph\u1ea3i ai c\u0169ng gi\u1ea3i th\u00edch \u0111\u01b0\u1ee3c kh\u00e1i ni\u1ec7m v\u1eadn t\u1ed1c l\u00e0 g\u00ec? C\u00f4ng th\u1ee9c t\u00ednh nh\u01b0 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_disable_autopaging":false},"categories":[7],"tags":[],"class_list":["post-3430","post","type-post","status-publish","format-standard","hentry","category-vat-ly"],"_links":{"self":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/3430","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/comments?post=3430"}],"version-history":[{"count":0,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/3430\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/media?parent=3430"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/categories?post=3430"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/tags?post=3430"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}