Ghi ch\u00fa: T\u00e0i li\u1ec7u tr\u00edch d\u1eabn<\/p>\n\n\n\n
Chuy\u1ec3n \u0111\u1ed9ng c\u01a1 h\u1ecdc l\u00e0 b\u00e0i \u0111\u1ea7u ti\u00ean trong m\u00f4n V\u1eadt l\u00fd kh\u1ed1i 8. Tuy kh\u00f4ng c\u00f3 qu\u00e1 nhi\u1ec1u l\u00fd thuy\u1ebft l\u1eabn c\u00f4ng th\u1ee9c kh\u00f3 nh\u01b0ng b\u00e0i h\u1ecdc n\u00e0y l\u00e0 n\u1ec1n t\u1ea3ng cho to\u00e0n b\u1ed9 ch\u01b0\u01a1ng c\u01a1 h\u1ecdc. \u0110\u1ec3 h\u1ecdc t\u1ed1t ph\u1ea7n n\u00e0y, h\u1ecdc sinh<\/a> c\u1ea7n n\u1eafm r\u00f5 b\u1ea3n ch\u1ea5t c\u1ee7a v\u1ea5n \u0111\u1ec1 c\u0169ng nh\u01b0 c\u00e1c \u0111\u1ecbnh ngh\u0129a v\u00e0 c\u00f4ng th\u1ee9c.<\/p>\n\n\n\n C\u1ee5 th\u1ec3, b\u00e0i gi\u1ea3ng n\u00e0y gi\u00fap c\u00e1c em x\u00e1c \u0111\u1ecbnh \u0111\u01b0\u1ee3c nh\u1eefng ph\u1ea7n sau: kh\u00e1i ni\u1ec7m c\u1ee7a chuy\u1ec3n \u0111\u1ed9ng c\u01a1 h\u1ecdc, c\u00e1ch nh\u1eadn bi\u1ebft m\u1ed9t v\u1eadt chuy\u1ec3n \u0111\u1ed9ng hay \u0111\u1ee9ng y\u00ean, t\u00ednh t\u01b0\u01a1ng \u0111\u1ed1i c\u1ee7a chuy\u1ec3n \u0111\u1ed9ng v\u00e0 \u0111\u1ee9ng y\u00ean. B\u00ean c\u1ea1nh \u0111\u00f3, c\u00e1c em c\u0169ng n\u00ean luy\u1ec7n k\u1ef9 c\u00e1c b\u00e0i t\u1eadp v\u00e0 v\u00ed d\u1ee5 minh h\u1ecda trong s\u00e1ch gi\u00e1o khoa \u0111\u1ec3 hi\u1ec3u t\u01b0\u1eddng t\u1eadn \u0111\u01b0\u1ee3c ph\u1ea7n l\u00fd thuy\u1ebft.<\/p>\n\n\n\n L\u00fd thuy\u1ebft chuy\u1ec3n \u0111\u1ed9ng c\u01a1 h\u1ecdc l\u1edbp 8<\/p>\n\n\n\n C\u00e1ch x\u00e1c \u0111\u1ecbnh m\u1ed9t v\u1eadt chuy\u1ec3n \u0111\u1ed9ng hay \u0111\u1ee9ng y\u00ean<\/p>\n\n\n\n Trong cu\u1ed9c s\u1ed1ng th\u1ef1c t\u1ebf, ta c\u00f3 th\u1ec3 th\u1ea5y \u0111\u01b0\u1ee3c m\u1ed9t v\u1eadt chuy\u1ec3n \u0111\u1ed9ng hay \u0111\u1ee9ng y\u00ean b\u1eb1ng m\u1eaft th\u01b0\u1eddng. Tuy nhi\u00ean trong v\u1eadt l\u00fd th\u00ec kh\u00f4ng nh\u01b0 v\u1eady.<\/p>\n\n\n\n Trong m\u00f4n h\u1ecdc n\u00e0y, ta nh\u1eadn bi\u1ebft \u0111\u01b0\u1ee3c m\u1ed9t v\u1eadt c\u00f3 \u0111ang chuy\u1ec3n \u0111\u1ed9ng hay v\u1eabn \u0111\u1ee9ng y\u00ean d\u1ef1a v\u00e0o v\u1ecb tr\u00ed c\u1ee7a v\u1eadt \u0111\u00f3 v\u1edbi m\u1ed9t v\u1eadt \u0111\u01b0\u1ee3c ch\u1ecdn l\u00e0m m\u1ed1c.<\/p>\n\n\n\n V\u1eadt m\u1ed1c th\u01b0\u1eddng \u0111\u01b0\u1ee3c ch\u1ecdn l\u00e0 nh\u1eefng v\u1eadt g\u1eafn li\u1ec1n v\u1edbi Tr\u00e1i \u0110\u1ea5t ho\u1eb7c l\u00e0 Tr\u00e1i \u0110\u1ea5t lu\u00f4n nh\u01b0: nh\u00e0 c\u1eeda, c\u00e2y c\u1ed1i, bi\u1ec3n hi\u1ec7u\u2026 Tuy nhi\u00ean trong nhi\u1ec1u b\u00e0i t\u1eadp v\u1ec1 chuy\u1ec3n \u0111\u1ed9ng, ng\u01b0\u1eddi ra \u0111\u1ec1 c\u00f3 th\u1ec3 \u0111\u1eb7t c\u1ea3 nh\u1eefng v\u1eadt \u0111ang di chuy\u1ec3n l\u00e0m v\u1eadt m\u1ed1c. H\u1ecdc sinh<\/a> c\u1ea7n l\u01b0u \u00fd x\u00e1c \u0111\u1ecbnh \u0111\u00fang v\u1eadt m\u1ed1c tr\u01b0\u1edbc khi \u0111\u01b0a ra k\u1ebft lu\u1eadn v\u1ec1 s\u1ef1 chuy\u1ec3n \u0111\u1ed9ng.<\/p>\n\n\n\n S\u1ef1 chuy\u1ec3n \u0111\u1ed9ng c\u00f3 t\u00ednh t\u01b0\u01a1ng \u0111\u1ed1i<\/p>\n\n\n\n T\u1eeb nh\u1eefng ph\u00e2n t\u00edch tr\u00ean, ta \u0111\u01b0a ra k\u1ebft lu\u1eadn v\u1ec1 \u0111\u1ecbnh ngh\u0129a nh\u01b0 sau:<\/p>\n\n\n\n S\u1ef1 thay \u0111\u1ed5i v\u1ecb tr\u00ed c\u1ee7a m\u1ed9t v\u1eadt theo th\u1eddi gian so v\u1edbi v\u1eadt kh\u00e1c \u0111\u01b0\u1ee3c ch\u1ecdn l\u00e0m m\u1ed1c g\u1ecdi l\u00e0 chuy\u1ec3n \u0111\u1ed9ng c\u01a1 h\u1ecdc.<\/p>\n\n\n\n V\u00ed d\u1ee5:<\/p>\n\n\n\n T\u00e0u \u0111ang ch\u1ea1y tr\u00ean bi\u1ec3n suy ra t\u00e0u c\u00f3 s\u1ef1 d\u1ecbch chuy\u1ec3n c\u01a1 h\u1ecdc so v\u1edbi Tr\u00e1i \u0110\u1ea5t.<\/p>\n\n\n\n M\u1ed9t ng\u01b0\u1eddi \u0111ang b\u01b0\u1edbc \u0111i tr\u00ean \u0111\u01b0\u1eddng suy ra ng\u01b0\u1eddi \u0111\u00f3 c\u00f3 s\u1ef1 d\u1ecbch chuy\u1ec3n c\u01a1 h\u1ecdc so v\u1edbi m\u1ed9t ng\u00f4i nh\u00e0 b\u1ea5t k\u1ef3 ven \u0111\u01b0\u1eddng.<\/p>\n\n\n\n T\u00ednh t\u01b0\u01a1ng \u0111\u1ed1i c\u1ee7a chuy\u1ec3n \u0111\u1ed9ng v\u00e0 \u0111\u1ee9ng y\u00ean<\/p>\n\n\n\n T\u00ednh t\u01b0\u01a1ng \u0111\u1ed1i \u1edf \u0111\u00e2y l\u00e0 ch\u1ec9 m\u1ed9t v\u1eadt b\u1ea5t k\u1ef3 s\u1ebd c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c k\u1ebft lu\u1eadn l\u00e0 \u0111ang chuy\u1ec3n \u0111\u1ed9ng hay \u0111\u1ee9ng y\u00ean c\u00f2n t\u00f9y thu\u1ed9c v\u00e0o v\u1eadt \u0111\u01b0\u1ee3c ch\u1ecdn l\u00e0m m\u1ed1c. \u0110\u00f3 c\u0169ng l\u00e0 c\u00e1ch m\u00e0 d\u1ea1ng b\u00e0i t\u1eadp chuy\u1ec3n \u0111\u1ed9ng ph\u00e1t tri\u1ec3n theo m\u1ee9c kh\u00f3 v\u00e0 ph\u1ee9c t\u1ea1p h\u01a1n. H\u1ecdc sinh<\/a> ph\u1ea3i ch\u1ecdn \u0111\u00fang v\u1ecb tr\u00ed v\u1eadt m\u1ed1c trong kh\u1ea3o s\u00e1t d\u1ecbch chuy\u1ec3n \u0111ang ti\u1ebfn h\u00e0nh.<\/p>\n\n\n\n V\u00ed d\u1ee5:<\/p>\n\n\n\n T\u00ecnh hu\u1ed1ng t\u00e0u \u0111i\u1ec7n \u0111ang ch\u1ea1y v\u00e0 c\u00e1i c\u00e2y ven \u0111\u01b0\u1eddng. Ta ch\u1ecdn c\u00e1i c\u00e2y ven \u0111\u01b0\u1eddng l\u00e0m m\u1ed1c, v\u1eady th\u00ec t\u00e0u \u0111i\u1ec7n c\u00f3 s\u1ef1 d\u1ecbch chuy\u1ec3n c\u01a1 h\u1ecdc so v\u1edbi c\u00e1i c\u00e2y.<\/p>\n\n\n\n T\u00ecnh hu\u1ed1ng t\u00e0u \u0111i\u1ec7n \u0111ang ch\u1ea1y v\u00e0 m\u1ed9t ng\u01b0\u1eddi ng\u1ed3i trong t\u00e0u \u0111i\u1ec7n. Ta ch\u1ecdn ng\u01b0\u1eddi ng\u1ed3i im l\u00e0m m\u1ed1c, v\u1eady th\u00ec t\u00e0u \u0111i\u1ec7n \u0111ang kh\u00f4ng c\u00f3 s\u1ef1 d\u1ecbch chuy\u1ec3n c\u01a1 h\u1ecdc so v\u1edbi ng\u01b0\u1eddi \u0111\u00f3.<\/p>\n\n\n\n T\u1eeb \u0111\u00f3 suy ra k\u1ebft lu\u1eadn, m\u1ed9t v\u1eadt c\u00f3 th\u1ec3 \u0111\u1ee9ng y\u00ean v\u1edbi v\u1eadt n\u00e0y nh\u01b0ng c\u0169ng c\u00f3 th\u1ec3 chuy\u1ec3n \u0111\u1ed9ng v\u1edbi v\u1eadt kh\u00e1c. S\u1ef1 chuy\u1ec3n \u0111\u1ed9ng v\u00e0 s\u1ef1 \u0111\u1ee9ng y\u00ean ph\u1ee5 thu\u1ed9c v\u00e0o v\u1eadt m\u1ed1c \u0111\u01b0\u1ee3c ch\u1ecdn. \u0110\u00f3 ch\u00ednh l\u00e0 t\u00ednh t\u01b0\u01a1ng \u0111\u1ed1i c\u1ee7a chuy\u1ec3n \u0111\u1ed9ng c\u01a1 h\u1ecdc v\u00e0 \u0111\u1ee9ng y\u00ean.<\/p>\n\n\n\n Khi n\u00e0o v\u1eadt \u0111\u1ee9ng y\u00ean<\/p>\n\n\n\n M\u1ed9t s\u1ed1 d\u1ea1ng chuy\u1ec3n \u0111\u1ed9ng c\u01a1 h\u1ecdc hay g\u1eb7p<\/p>\n\n\n\n Qu\u1ef9 \u0111\u1ea1o chuy\u1ec3n \u0111\u1ed9ng l\u00e0 \u0111\u01b0\u1eddng m\u00e0 v\u1eadt v\u1ea1ch ra khi chuy\u1ec3n \u0111\u1ed9ng. Th\u01b0\u1eddng th\u00ec ta s\u1ebd hay g\u1eb7p nh\u1eefng d\u1ea1ng chuy\u1ec3n \u0111\u1ed9ng nh\u01b0 sau:<\/p>\n\n\n\n Chuy\u1ec3n \u0111\u1ed9ng th\u1eb3ng: Qu\u1ef9 \u0111\u1ea1o chuy\u1ec3n \u0111\u1ed9ng l\u00e0 \u0111\u01b0\u1eddng th\u1eb3ng, v\u00ed d\u1ee5 nh\u01b0 m\u1ed9t v\u1eadt r\u01a1i t\u1ef1 do t\u1eeb tr\u00ean cao xu\u1ed1ng.<\/p>\n\n\n\n Chuy\u1ec3n \u0111\u1ed9ng cong: Qu\u1ef9 \u0111\u1ea1o chuy\u1ec3n \u0111\u1ed9ng l\u00e0 \u0111\u01b0\u1eddng cong, v\u00ed d\u1ee5 nh\u01b0 n\u00e9m, chuy\u1ec1n m\u1ed9t v\u1eadt.<\/p>\n\n\n\n Chuy\u1ec3n \u0111\u1ed9ng tr\u00f2n: Qu\u1ef9 \u0111\u1ea1o chuy\u1ec3n \u0111\u1ed9ng l\u00e0 \u0111\u01b0\u1eddng tr\u00f2n, v\u00ed d\u1ee5 nh\u01b0 c\u00e1nh qu\u1ea1t quay.<\/p>\n\n\n\n M\u1ed7i lo\u1ea1i h\u00ecnh chuy\u1ec3n \u0111\u1ed9ng s\u1ebd c\u00f3 nh\u1eefng c\u00f4ng th\u1ee9c t\u00ednh to\u00e1n \u0111i k\u00e8m kh\u00e1c nhau. \u0110\u00f3 l\u00e0 l\u00fd do h\u1ecdc sinh<\/a> ph\u1ea3i n\u1eafm r\u00f5 c\u00e1ch nh\u1eadn bi\u1ebft c\u1ee7a c\u00e1c lo\u1ea1i chuy\u1ec3n \u0111\u1ed9ng.<\/p>\n\n\n\n T\u00ecm hi\u1ec3u th\u00eam v\u1ec1 r\u00f2ng r\u1ecdc c\u1ed1 \u0111\u1ecbnh<\/p><\/blockquote>\n\n\n\n S\u1ef1 n\u1edf v\u00ec nhi\u1ec7t c\u1ee7a ch\u1ea5t r\u1eafn<\/p>\n\n\n\n Gi\u1ea3i b\u00e0i t\u1eadp V\u1eadt L\u00fd l\u1edbp 8 b\u00e0i 1 \u2013 Chuy\u1ec3n \u0111\u1ed9ng c\u01a1 h\u1ecdc<\/p>\n\n\n\n V\u1edbi b\u00e0i 1 chuy\u1ec3n \u0111\u1ed9ng c\u01a1, h\u1ecdc sinh<\/a> c\u00f3 th\u1ec3 tham kh\u1ea3o nh\u1eefng d\u1ea1ng b\u00e0i t\u1eadp m\u1eabu nh\u01b0 sau.<\/p>\n\n\n\n B\u00e0i 1<\/p>\n\n\n\n \u0110\u1ec1 b\u00e0i: C\u00e1ch x\u00e1c \u0111\u1ecbnh s\u1ef1 chuy\u1ec3n \u0111\u1ed9ng hay \u0111\u1ee9ng y\u00ean c\u1ee7a m\u1ed9t v\u1eadt nh\u01b0: \u00f4 t\u00f4 tr\u00ean \u0111\u01b0\u1eddng, m\u1ed9t chi\u1ebfc thuy\u1ec1n tr\u00ean s\u00f4ng, m\u1ed9t \u0111\u00e1m m\u00e2y tr\u00ean tr\u1eddi\u2026<\/p>\n\n\n\n B\u00e0i l\u00e0m:<\/p>\n\n\n\n Theo l\u00fd thuy\u1ebft, \u0111\u1ec3 x\u00e1c \u0111\u1ecbnh \u0111\u01b0\u1ee3c c\u00e1c v\u1eadt cho tr\u01b0\u1edbc \u0111ang chuy\u1ec3n \u0111\u1ed9ng hay \u0111\u1ee9ng y\u00ean, ta s\u1ebd so s\u00e1nh v\u1ecb tr\u00ed c\u1ee7a v\u1eadt so v\u1edbi v\u1eadt kh\u00e1c theo th\u1eddi gian:<\/p>\n\n\n\n Ch\u1ecdn v\u1eadt m\u1ed1c c\u1ee7a \u00f4 t\u00f4 l\u00e0 v\u1eadt b\u1ea5t k\u1ef3 \u0111\u1ee9ng y\u00ean tr\u00ean \u0111\u01b0\u1eddng (bi\u1ec3n hi\u1ec7u, c\u1ed9t \u0111i\u1ec7n\u2026)<\/p>\n\n\n\n Ch\u1ecdn v\u1eadt m\u1ed1c c\u1ee7a thuy\u1ec1n l\u00e0 v\u1eadt b\u1ea5t k\u1ef3 \u0111\u1ee9ng y\u00ean tr\u00ean b\u1edd s\u00f4ng (c\u00e2y c\u1ed1i, nh\u00e0 c\u1eeda\u2026)<\/p>\n\n\n\n Ch\u1ecdn v\u1eadt m\u1ed1c c\u1ee7a \u0111\u00e1m m\u00e2y l\u00e0 v\u1eadt b\u1ea5t k\u1ef3 g\u1eafn v\u1edbi Tr\u00e1i \u0110\u1ea5t (c\u1ed9t \u0111\u00e8n, t\u00f2a nh\u00e0\u2026)<\/p>\n\n\n\n T\u1eeb \u0111\u00f3 ta r\u00fat ra \u0111\u01b0\u1ee3c v\u1eadt \u0111\u00f3 \u0111\u1ee9ng y\u00ean n\u1ebfu v\u1ecb tr\u00ed kh\u00f4ng thay \u0111\u1ed5i theo th\u1eddi gian so v\u1edbi v\u1eadt l\u00e0m m\u1ed1c. Ng\u01b0\u1ee3c l\u1ea1i, v\u1eadt \u0111\u00f3 chuy\u1ec3n \u0111\u1ed9ng khi v\u1ecb tr\u00ed thay \u0111\u1ed5i so v\u1edbi v\u1eadt l\u00e0m m\u1ed1c.<\/p>\n\n\n\n B\u00e0i t\u1eadp \u1ee9ng d\u1ee5ng<\/p>\n\n\n\n B\u00e0i 2 \u2013 Chuy\u1ec3n \u0111\u1ed9ng c\u01a1 h\u1ecdc<\/p>\n\n\n\n \u0110\u1ec1 b\u00e0i: M\u1ed9t \u0111o\u00e0n t\u00e0u \u0111ang ch\u1ea1y v\u00e0o trong ga. Ch\u1ecdn \u0111\u00e1p \u00e1n SAI trong c\u00e1c \u0111\u00e1p \u00e1n d\u01b0\u1edbi \u0111\u00e2y:<\/p>\n\n\n\n \u0110o\u00e0n t\u00e0u \u0111ang \u0111\u1ee9ng y\u00ean so v\u1edbi ng\u01b0\u1eddi \u0111i\u1ec1u khi\u1ec3n t\u00e0u.<\/p>\n\n\n\n \u0110o\u00e0n t\u00e0u \u0111ang d\u1ecbch chuy\u1ec3n so v\u1edbi nh\u00e0 ga.<\/p>\n\n\n\n \u0110o\u00e0n t\u00e0u \u0111ang d\u1ecbch chuy\u1ec3n so v\u1edbi ng\u01b0\u1eddi \u0111ang ng\u1ed3i tr\u00ean t\u00e0u.<\/p>\n\n\n\n \u0110o\u00e0n t\u00e0u \u0111ang d\u1ecbch chuy\u1ec3n so v\u1edbi nh\u1eefng ng\u01b0\u1eddi \u0111ang \u0111\u1ee9ng hai b\u00ean \u0111\u01b0\u1eddng.<\/p>\n\n\n\n \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 C. Gi\u1ea3i th\u00edch: \u0110o\u00e0n t\u00e0u \u0111ang chuy\u1ec3n \u0111\u1ed9ng, khi \u0111\u00f3 ng\u01b0\u1eddi ng\u1ed3i tr\u00ean t\u00e0u c\u0169ng chuy\u1ec3n \u0111\u1ed9ng c\u00f9ng v\u1edbi t\u1ed1c \u0111\u1ed9 v\u00e0 th\u1eddi gian nh\u01b0 v\u1eady. Do \u0111\u00f3 \u0111o\u00e0n t\u00e0u \u0111ang \u0111\u1ee9ng y\u00ean so v\u1edbi ng\u01b0\u1eddi ng\u1ed3i tr\u00ean t\u00e0u.<\/p>\n\n\n\n B\u00e0i 3<\/p>\n\n\n\n \u0110\u1ec1 b\u00e0i: M\u1ed9t ng\u01b0\u1eddi tr\u00ean t\u00e0u A th\u1ea5y t\u00e0u B \u0111ang di chuy\u1ec3n ti\u1ebfn v\u1ec1 ph\u00eda tr\u01b0\u1edbc. C\u00f2n ng\u01b0\u1eddi tr\u00ean t\u00e0u B th\u1ea5y t\u00e0u C c\u0169ng \u0111ang di chuy\u1ec3n v\u1ec1 ph\u00eda tr\u01b0\u1edbc. V\u1eady th\u00ec ng\u01b0\u1eddi tr\u00ean t\u00e0u A s\u1ebd nh\u00ecn th\u1ea5y t\u00e0u C nh\u01b0 th\u1ebf n\u00e0o?<\/p>\n\n\n\n \u0111\u1ee9ng y\u00ean<\/p>\n\n\n\n l\u00f9i ra ph\u00eda sau<\/p>\n\n\n\n ti\u1ebfn v\u1ec1 ph\u00eda tr\u01b0\u1edbc<\/p>\n\n\n\n ti\u1ebfn v\u1ec1 ph\u00eda tr\u01b0\u1edbc r\u1ed3i sau \u0111\u00f3 l\u00f9i ra ph\u00eda sau<\/p>\n\n\n\n \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 C. Gi\u1ea3i th\u00edch: V\u1edbi v\u1eadt m\u1ed1c l\u00e0 ng\u01b0\u1eddi A th\u00ec t\u00e0u B \u0111ang di chuy\u1ec3n v\u1ec1 ph\u00eda tr\u01b0\u1edbc. V\u1edbi v\u1eadt m\u1ed1c l\u00e0 ng\u01b0\u1eddi B (hay t\u00e0u B, v\u00ec ng\u01b0\u1eddi v\u00e0 t\u00e0u \u0111\u1ee9ng y\u00ean so v\u1edbi nhau) th\u00ec t\u00e0u C di chuy\u1ec3n v\u1ec1 ph\u00eda tr\u01b0\u1edbc. Theo t\u00ednh ch\u1ea5t b\u1eafc c\u1ea7u suy ra v\u1edbi ng\u01b0\u1eddi A, t\u00e0u C c\u0169ng di chuy\u1ec3n v\u1ec1 ph\u00eda tr\u01b0\u1edbc.<\/p>\n\n\n\n B\u00e0i 4<\/p>\n\n\n\n \u0110\u1ec1 b\u00e0i: S\u1ef1 chuy\u1ec3n \u0111\u1ed9ng n\u00e0o d\u01b0\u1edbi \u0111\u00e2y kh\u00f4ng \u0111\u01b0\u1ee3c t\u00ednh l\u00e0 chuy\u1ec3n \u0111\u1ed9ng c\u01a1 h\u1ecdc?<\/p>\n\n\n\n S\u1ef1 r\u01a1i t\u1ef1 do c\u1ee7a c\u00e0nh c\u00e2y<\/p>\n\n\n\n S\u1ef1 di chuy\u1ec3n c\u1ee7a m\u1eb7t tr\u1eddi t\u1eeb \u0110\u00f4ng sang T\u00e2y<\/p>\n\n\n\n S\u1ef1 g\u1ea5p kh\u00fac \u0111\u01b0\u1eddng di chuy\u1ec3n c\u1ee7a tia s\u00e1ng t\u1eeb kh\u00f4ng kh\u00ed v\u00e0o n\u01b0\u1edbc<\/p>\n\n\n\n S\u1ef1 \u0111ong \u0111\u01b0a c\u1ee7a \u0111u quay<\/p>\n\n\n\n \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 C. Gi\u1ea3i th\u00edch: V\u00ec s\u1ef1 g\u1ea5p kh\u00fac c\u1ee7a tia s\u00e1ng kh\u00f4ng c\u00f3 t\u00e1c \u0111\u1ed9ng t\u1eeb c\u01a1 h\u1ecdc n\u00ean kh\u00f4ng \u0111\u01b0\u1ee3c t\u00ednh l\u00e0 chuy\u1ec3n \u0111\u1ed9ng c\u01a1 h\u1ecdc.<\/p>\n\n\n\n B\u00e0i 5<\/p>\n\n\n\n \u0110\u1ec1 b\u00e0i: C\u00f3 \u00fd ki\u1ebfn cho r\u1eb1ng: \u201cN\u1ebfu kho\u1ea3ng c\u00e1ch t\u1eeb v\u1eadt c\u1ea7n x\u00e9t t\u1edbi v\u00e2\u0323t m\u1ed1c kh\u00f4ng c\u00f3 thay \u0111\u1ed5i th\u00ec v\u1eadt \u0111\u1ee9ng y\u00ean so v\u1edbi v\u1eadt m\u1ed1c\u201d. H\u00e3y cho bi\u1ebft, c\u00e1ch n\u00f3i nh\u01b0 th\u1ebf c\u00f3 ph\u1ea3i lu\u00f4n \u0111\u00fang hay kh\u00f4ng? Ch\u1ee9ng minh b\u1eb1ng v\u00ed d\u1ee5 minh h\u1ecda cho \u0111\u00e1p \u00e1n c\u1ee7a m\u00ecnh.<\/p>\n\n\n\n B\u00e0i l\u00e0m<\/p>\n\n\n\n C\u00e1ch ph\u00e1t bi\u1ec3u nh\u01b0 v\u00e2\u0323y la\u0300 SAI v\u00ec trong chuy\u1ec3n \u0111\u1ed9ng c\u01a1 h\u1ecdc tr\u00f2n, kho\u1ea3ng c\u00e1ch t\u1eeb v\u1eadt c\u1ea7n x\u00e9t t\u1edbi v\u1eadt m\u1ed1c kh\u00f4ng h\u1ec1 thay \u0111\u1ed5i.<\/p>\n\n\n\n V\u00ed d\u1ee5 ch\u1ee9ng minh: X\u00e9t chuy\u1ec3n \u0111\u1ed9ng v\u00f2ng \u0111u quay m\u1eb7t tr\u1eddi, m\u1eb7c d\u00f9 kho\u1ea3ng c\u00e1ch t\u1eeb c\u00e1c bu\u1ed3ng ng\u1ed3i cho kh\u00e1ch \u0111\u1ebfn tr\u1ee5c ch\u00ednh gi\u1eefa kh\u00f4ng thay \u0111\u1ed5i nh\u01b0ng v\u1ecb tr\u00ed c\u1ee7a bu\u1ed3ng ng\u1ed3i thay \u0111\u1ed5i theo theo th\u1eddi gian so v\u1edbi tr\u1ee5c ch\u00ednh gi\u1eefa n\u00ean ta v\u1eabn n\u00f3i bu\u1ed3ng ng\u1ed3i chuy\u1ec3n \u0111\u1ed9ng so v\u1edbi tr\u1ee5c.<\/p>\n\n\n\n V\u00ed d\u1ee5 v\u1ec1 c\u00e1c lo\u1ea1i chuy\u1ec3n \u0111\u1ed9ng<\/p>\n\n\n\n Tham kh\u1ea3o th\u00eam v\u1ec1 b\u00e0i h\u1ecdc V\u1eadn t\u1ed1c trung b\u00ecnh<\/p>\n\n\n\n K\u1ebft lu\u1eadn<\/p>\n\n\n\n B\u00e0i vi\u1ebft tr\u00ean s\u1ebd gi\u00fap c\u00e1c em n\u1eafm \u0111\u01b0\u1ee3c ph\u1ea7n l\u00fd thuy\u1ebft c\u01a1 b\u1ea3n nh\u1ea5t c\u1ee7a ch\u01b0\u01a1ng \u0111\u1ea7u V\u1eadt L\u00fd 8. To\u00e0n b\u1ed9 ph\u1ea7n n\u00e0y kh\u00f4ng kh\u00f3. Tuy nhi\u00ean n\u1ebfu kh\u00f4ng hi\u1ec3u r\u00f5 b\u1ea3n ch\u1ea5t v\u1ea5n \u0111\u1ec1 th\u00ec s\u1ebd g\u00e2y ra sai s\u00f3t trong nh\u1eefng b\u00e0i t\u1eadp ph\u1ee9c t\u1ea1p h\u01a1n sau n\u00e0y. Ch\u00fang t\u00f4i \u0111\u00e3 li\u1ec7t k\u00ea \u0111\u1ea7y \u0111\u1ee7 c\u00e1c kh\u00e1i ni\u1ec7m kh\u00e1c nhau xung quanh b\u00e0i h\u1ecdc. M\u1ed7i ph\u1ea7n \u0111\u1ec1u c\u00f3 v\u00ed d\u1ee5 minh h\u1ecda r\u00f5 r\u00e0ng \u0111i k\u00e8m. Ph\u1ea7n b\u00e0i t\u1eadp \u1edf d\u01b0\u1edbi gi\u00fap c\u00e1c em luy\u1ec7n t\u1eadp l\u1ea1i nh\u1eefng l\u00fd thuy\u1ebft v\u1eeba m\u1edbi ti\u1ebfp thu, g\u00f3p ph\u1ea7n c\u1ee7ng c\u1ed1 c\u0103n b\u1ea3n v\u1eefng ch\u1eafc h\u01a1n. Cu\u1ed1i c\u00f9ng, xin ch\u00fac c\u00e1c em h\u1ecdc sinh<\/a> c\u00f3 th\u1ec3 h\u1ecdc t\u1ed1t ph\u1ea7n chuy\u1ec3n \u0111\u1ed9ng c\u01a1 h\u1ecdc trong m\u00f4n V\u1eadt L\u00fd 8.<\/p>\n\n\n\n T\u00ecm \u0111\u1ecdc th\u00eam c\u00e1c th\u00f4ng tin b\u00e0i h\u1ecdc kh\u00e1c c\u00f9ng ch\u1ee7 \u0111\u1ec1<\/p><\/blockquote>\n\n\n\n L\u1ef1c k\u1ebf ph\u00e9p \u0111o l\u1ef1c tr\u1ecdng l\u01b0\u1ee3ng v\u00e0 kh\u1ed1i l\u01b0\u1ee3ng \u2013 V\u1eadt l\u00fd 6<\/p>\n\n\n\n\n\n\n","protected":false},"excerpt":{"rendered":" Ghi ch\u00fa: T\u00e0i li\u1ec7u tr\u00edch d\u1eabn Chuy\u1ec3n \u0111\u1ed9ng c\u01a1 h\u1ecdc l\u00e0 b\u00e0i \u0111\u1ea7u ti\u00ean trong m\u00f4n V\u1eadt l\u00fd kh\u1ed1i 8. Tuy kh\u00f4ng c\u00f3 qu\u00e1 nhi\u1ec1u l\u00fd thuy\u1ebft l\u1eabn c\u00f4ng th\u1ee9c kh\u00f3 nh\u01b0ng b\u00e0i h\u1ecdc n\u00e0y l\u00e0 n\u1ec1n t\u1ea3ng cho to\u00e0n b\u1ed9 ch\u01b0\u01a1ng c\u01a1 h\u1ecdc. \u0110\u1ec3 h\u1ecdc t\u1ed1t ph\u1ea7n n\u00e0y, h\u1ecdc sinh c\u1ea7n n\u1eafm r\u00f5 b\u1ea3n […]<\/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":[1],"tags":[],"class_list":["post-1159","post","type-post","status-publish","format-standard","hentry","category-general"],"_links":{"self":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/1159","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=1159"}],"version-history":[{"count":0,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/1159\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/media?parent=1159"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/categories?post=1159"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/tags?post=1159"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}