B\u00e0i 15 : B\u00e0i to\u00e1n v\u1ec1 chuy\u1ec3n \u0111\u1ed9ng n\u00e9m ngang<\/h2>\n\n\n\n

C1<\/strong> (trang 86 sgk V\u1eadt L\u00fd 10): H\u00e3y \u00e1p d\u1ee5ng \u0111\u1ecbnh lu\u1eadt II Niu \u2013 T\u01a1n theo m\u1ed7i tr\u1ee5c t\u1ecda \u0111\u1ed9 \u0111\u1ec3 t\u00ecm c\u00e1c gia t\u1ed1c a_{x<\/sub>, ay<\/sub> c\u1ee7a hai chuy\u1ec3n \u0111\u1ed9ng th\u00e0nh ph\u1ea7n. K\u1ebft h\u1ee3p v\u1edbi \u0111i\u1ec1u ki\u1ec7n ban \u0111\u1ea7u v\u1ec1 v\u1eadn t\u1ed1c (vox<\/sub>, voy<\/sub>), h\u00e3y x\u00e1c \u0111\u1ecbnh t\u00ednh ch\u1ea5t c\u1ee7a m\u1ed7i chuy\u1ec3n \u0111\u1ed9ng th\u00e0nh ph\u1ea7n.<\/p>\n\n\n\n}

Tr\u1ea3 l\u1eddi:<\/strong><\/ins><\/p>\n\n\n\n

<\/figure>\n\n\n\n

C2<\/strong> (trang 87 sgk V\u1eadt L\u00fd 10): M\u1ed9t v\u1eadt \u0111\u01b0\u1ee3c n\u00e9m ngang \u1edf \u0111\u1ed9 cao h = 80 m v\u1edbi v\u1eadn t\u1ed1c ban \u0111\u1ea7u v_{0<\/sub> = 20 m\/s. L\u1ea5y g = 10 m\/s^{2<\/sup>.<\/p>\n\n\n\n}}

a)\tT\u00ednh th\u1eddi gian chuy\u1ec3n \u0111\u1ed9ng v\u00e0 t\u1ea7m bay xa c\u1ee7a v\u1eadt.<\/p>\n\n\n\n

b)\tL\u1eadp ph\u01b0\u01a1ng tr\u00ecnh qu\u1ef9 \u0111\u1ea1o c\u1ee7a v\u1eadt.<\/ins><\/p>\n\n\n\n

Tr\u1ea3 l\u1eddi:<\/strong><\/p>\n\n\n\n

a)\tTh\u1eddi gian v\u1eadt chuy\u1ec3n \u0111\u1ed9ng b\u1eb1ng th\u1eddi gian v\u1eadt r\u01a1i theo theo ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng n\u00ean ta c\u00f3: \n<\/p>\n\n\n\n

<\/figure>\n\n\n\n

T\u1ea7m bay xa c\u1ee7a v\u1eadt b\u1eb1ng qu\u1ea3ng \u0111\u01b0\u1eddng v\u1eadt chuy\u1ec3n \u0111\u1ed9ng \u0111\u1ec1u theo ph\u01b0\u01a1ng ngang trong th\u1eddi gian t: L = v_{o<\/sub>t = 20.4 = 80 (m)\n<\/p>\n\n\n\n}

b) \u00c1p d\u1ee5ng c\u00f4ng th\u1ee9c ph\u01b0\u01a1ng tr\u00ecnh qu\u1ef9 \u0111\u1ea1o (trang 86 sgk), ta c\u00f3 ph\u01b0\u01a1ng tr\u00ecnh qu\u1ef9 \u0111\u1ea1o c\u1ee7a v\u1eadt l\u00e0:\n<\/p>\n\n\n\n

<\/figure>\n\n\n\n

C3<\/strong> (trang 87 sgk V\u1eadt L\u00fd 10): Th\u00ed nghi\u1ec7m tr\u00ean \u0111\u00e3 x\u00e1c nh\u1eadn \u0111i\u1ec1u g\u00ec?<\/p>\n\n\n\n

Tr\u1ea3 l\u1eddi:<\/strong><\/p>\n\n\n\n

Th\u00ed nghi\u1ec7m x\u00e1c nh\u1eadn, d\u01b0\u1edbi t\u00e1c d\u1ee5ng c\u1ee7a tr\u1ecdng l\u1ef1c, th\u1eddi gian v\u1eadt r\u01a1i ch\u1ec9 ph\u1ee5 thu\u1ed9c \u0111\u1ed9 cao m\u00e0 v\u1eadt s\u1ebd r\u01a1i h\u1ebft, kh\u00f4ng ph\u1ee5 thu\u1ed9c v\u00e0o v\u1eadn t\u1ed1c vector v_{0<\/sub> h\u01b0\u1edbng n\u1eb1m ngang (n\u00e9m ngang).<\/p>\n\n\n\n}

B\u00e0i 3 (trang 88 SGK V\u1eadt L\u00fd 10) :<\/strong> L\u1eadp ph\u01b0\u01a1ng tr\u00ecnh qu\u1ef9 \u0111\u1ea1o c\u1ee7a chuy\u1ec3n \u0111\u1ed9ng n\u00e9m ngang, c\u00e1c c\u00f4ng th\u1ee9c t\u00ednh th\u1eddi gian chuy\u1ec3n \u0111\u1ed9ng v\u00e0 t\u1ea7m n\u00e9m xa.<\/p>\n\n\n\n

L\u1eddi gi\u1ea3i:<\/strong><\/ins><\/p>\n\n\n\n

Theo tr\u1ee5c Ox, t\u1ecda \u0111\u1ed9 c\u1ee7a Mx l\u00e0: x = v_{0<\/sub>.t c\u0169ng ch\u00ednh l\u00e0 ho\u00e0nh \u0111\u1ed9 c\u1ee7a \u0111i\u1ec3m M chuy\u1ec3n \u0111\u1ed9ng n\u00e9m ngang. \n<\/p>\n\n\n\n}

<\/figure>\n\n\n\n

T\u1ea1i th\u1eddi \u0111i\u1ec3m t, \u0111i\u1ec3m M c\u00f3 tung \u0111\u1ed9 (t\u1ecda \u0111\u1ed9 c\u1ee7a M_{y<\/sub>):\n<\/p>\n\n\n\n}

<\/figure>\n\n\n\n

Th\u1ebf (1) v\u00e0o (2) \n<\/p>\n\n\n\n

<\/figure>\n\n\n\n

Th\u1eddi gian chuy\u1ec3n \u0111\u1ed9ng b\u1eb1ng th\u1eddi gian r\u01a1i t\u1ef1 do c\u1ee7a v\u1eadt \u0111\u01b0\u1ee3c th\u1ea3 t\u1eeb c\u00f9ng \u0111\u1ed9 cao:\n<\/p>\n\n\n\n

<\/figure>\n\n\n\n

T\u1ea7m n\u00e9m xa: \n<\/p>\n\n\n\n

<\/figure>\n\n\n\n

B\u00e0i 4 (trang 88 SGK V\u1eadt L\u00fd 10) :<\/strong> Bi A c\u00f3 \nkh\u1ed1i l\u01b0\u1ee3ng l\u1edbn g\u1ea5p \u0111\u00f4i bi B. C\u00f9ng m\u1ed9t l\u00fac t\u1ea1i m\u00e1i nh\u00e0, bi A \u0111\u01b0\u1ee3c th\u1ea3 r\u01a1i\n c\u00f2n bi B \u0111\u01b0\u1ee3c n\u00e9m theo ph\u01b0\u01a1ng ngang. B\u1ecf qua s\u1ee9c c\u1ea3n c\u1ee7a kh\u00f4ng kh\u00ed.<\/p>\n\n\n\n

H\u00e3y cho bi\u1ebft c\u00e2u n\u00e0o d\u01b0\u1edbi \u0111\u00e2y l\u00e0 c\u00e2u \u0111\u00fang?<\/ins><\/p>\n\n\n\n

A.\tA ch\u1ea1m \u0111\u1ea5t tr\u01b0\u1edbc<\/p>\n\n\n\n

B.\tA ch\u1ea1m \u0111\u1ea5t sau<\/p>\n\n\n\n

C.\tC\u1ea3 hai ch\u1ea1m \u0111\u1ea5t c\u00f9ng l\u00fac<\/p>\n\n\n\n

D.\tCh\u01b0a \u0111\u1ee7 th\u00f4ng tin \u0111\u1ec3 tr\u1ea3 l\u1eddi<\/p>\n\n\n\n

L\u1eddi gi\u1ea3i:<\/strong><\/p>\n\n\n\n

Ch\u1ecdn C. \n<\/p>\n\n\n\n

V\u00ec th\u1eddi gian r\u01a1i c\u1ee7a v\u1eadt n\u00e9m ngang v\u00e0 v\u1eadt r\u01a1i t\u1ef1 do t\u1eeb c\u00f9ng m\u1ed9t \u0111\u1ed9 cao l\u00e0 nh\u01b0 nhau. \u0110\u1ed3ng th\u1eddi th\u1eddi gian r\u01a1i t\u1ef1 do kh\u00f4ng ph\u1ee5 thu\u1ed9c kh\u1ed1i l\u01b0\u1ee3ng c\u1ee7a v\u1eadt. <\/p>\n\n\n\n

B\u00e0i 5 (trang 88 SGK V\u1eadt L\u00fd 10) :<\/strong> M\u1ed9t m\u00e1y \nbay bay theo ph\u01b0\u01a1ng ngang \u1edf \u0111\u1ed9 cao 10 km v\u1edbi t\u1ed1c \u0111\u1ed9 720 km\/h . Vi\u00ean phi \nc\u00f4ng ph\u1ea3i th\u1ea3 bom t\u1eeb xa c\u00e1ch m\u1ee5c ti\u00eau (theo ph\u01b0\u01a1ng ngang) bao nhi\u00eau \u0111\u1ec3 \nqu\u1ea3 bom r\u01a1i tr\u00fang m\u1ee5c ti\u00eau? L\u1ea5y g = 10 m\/s^{2<\/sup>. V\u1ebd m\u1ed9t c\u00e1ch g\u1ea7n \u0111\u00fang d\u1ea1ng qu\u1ef9 \u0111\u1ea1o c\u1ee7a qu\u1ea3 bom.<\/p>\n\n\n\n}

L\u1eddi gi\u1ea3i:<\/strong><\/ins><\/p>\n\n\n\n

H\u00ecnh minh h\u1ecda:<\/p>\n\n\n\n

<\/figure>\n\n\n\n

v_{0<\/sub> = 720 km\/h = 200m\/s, h = 10 km = 10000 m.\n<\/p>\n\n\n\n}

\u00c1p d\u1ee5ng c\u00f4ng th\u1ee9c t\u1ea7m n\u00e9m xa ta c\u00f3: \n<\/p>\n\n\n\n

<\/figure>\n\n\n\n

B\u00e0i 6 (trang 88 SGK V\u1eadt L\u00fd 10) :<\/strong> M\u1ed9t h\u00f2n \nbi l\u0103n d\u1ecdc theo m\u1ed9t c\u1ea1nh c\u1ee7a m\u1ed9t m\u1eb7t b\u00e0n h\u00ecnh ch\u1eef nh\u1eadt n\u1eb1m ngang cao h =\n 1,25 m. Khi ra kh\u1ecfi m\u00e9p b\u00e0n, n\u00f3 r\u01a1i xu\u1ed1ng n\u1ec1n nh\u00e0 t\u1ea1i \u0111i\u1ec3m c\u00e1ch m\u00e9p b\u00e0n\n L = 1,50 m (theo ph\u01b0\u01a1ng ngang)? L\u1ea5y g = 10 m\/s^{2<\/sup>. Th\u1eddi gian r\u01a1i c\u1ee7a h\u00f2n bi l\u00e0: <\/p>\n\n\n\n}

A.\t0,35 s <\/ins><\/p>\n\n\n\n

B. 0,125 s <\/p>\n\n\n\n

C. 0,5 s <\/p>\n\n\n\n

D. 0,25 s<\/p>\n\n\n\n

L\u1eddi gi\u1ea3i:<\/strong><\/p>\n\n\n\n

Ch\u1ecdn C.<\/p>\n\n\n\n

Chuy\u1ec3n \u0111\u1ed9ng c\u1ee7a bi r\u1eddi kh\u1ecfi m\u1eb7t b\u00e0n coi nh\u01b0 l\u00e0 chuy\u1ec3n \u0111\u1ed9ng n\u00e9m ngang\n v\u1edbi \u0111\u1ed9 cao ban \u0111\u1ea7u h = 1,25 m v\u00e0 c\u00f3 t\u1ea7m n\u00e9m xa l\u00e0 L = 1,50 m. Ta c\u00f3:<\/p>\n\n\n\n

<\/figure>\n\n\n\n

B\u00e0i 7 (trang 88 SGK V\u1eadt L\u00fd 10) :<\/strong> V\u1edbi s\u1ed1 li\u1ec7u c\u1ee7a b\u00e0i 6, h\u1ecfi t\u1ed1c \u0111\u1ed9 c\u1ee7a vi\u00ean bi l\u00fac r\u1eddi kh\u1ecfi b\u00e0n?<\/ins><\/p>\n\n\n\n

A.\t4,28 m\/s ;         B. 3 m\/s <\/p>\n\n\n\n

C. 12 m\/s ;         D. 6 m\/s<\/p>\n\n\n\n

L\u1eddi gi\u1ea3i:<\/strong><\/p>\n\n\n\n

– Ch\u1ecdn B<\/strong>.<\/p>\n\n\n\n

– \u00c1p d\u1ee5ng c\u00f4ng th\u1ee9c t\u1ea7m n\u00e9m xa.<\/p>\n\n\n\n

T\u1ed1c \u0111\u1ed9 c\u1ee7a vi\u00ean bi l\u1ee9c r\u1eddi kh\u1ecfi b\u00e0n l\u00e0:<\/p>\n\n\n\n

<\/figure>\n\n\n\n

<\/ins><\/p>\n","protected":false},"excerpt":{"rendered":"

B\u00e0i 15 : B\u00e0i to\u00e1n v\u1ec1 chuy\u1ec3n \u0111\u1ed9ng n\u00e9m ngang C1 (trang 86 sgk V\u1eadt L\u00fd 10): H\u00e3y \u00e1p d\u1ee5ng \u0111\u1ecbnh lu\u1eadt II Niu \u2013 T\u01a1n theo m\u1ed7i tr\u1ee5c t\u1ecda \u0111\u1ed9 \u0111\u1ec3 t\u00ecm c\u00e1c gia t\u1ed1c ax, ay c\u1ee7a hai chuy\u1ec3n \u0111\u1ed9ng th\u00e0nh ph\u1ea7n. K\u1ebft h\u1ee3p v\u1edbi \u0111i\u1ec1u ki\u1ec7n ban \u0111\u1ea7u v\u1ec1 v\u1eadn t\u1ed1c (vox, […]<\/p>\n","protected":false},"author":12,"featured_media":44133,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_mi_skip_tracking":false,"tdm_status":"","tdm_grid_status":""},"categories":[1640],"tags":[],"yoast_head":"\n