Lực hướng tâm và gia tốc hướng tâm

Home Lớp 10 Vật lý 10 - Sách kết nối tri thức Bài 32. Lực hướng tâm và gia tốc hướng tâmBài tập trung bình

{"common":{"save":0,"post_id":"8855","level":2,"total":10,"point":10,"point_extra":0},"segment":[{"id":"8324","mon_id":"1158790","chapter_id":"1159899","post_id":"8855","question":"M\u1ed9t v\u1ec7 tinh nhân t\u1ea1o chuy\u1ec3n \u0111\u1ed9ng tròn \u0111\u1ec1u quanh Trái \u0110\u1ea5t \u1edf \u0111\u1ed9 cao b\u1eb1ng bán kính R c\u1ee7a Trái \u0110\u1ea5t. L\u1ea5y gia t\u1ed1c r\u01a1i t\u1ef1 do t\u1ea1i m\u1eb7t \u0111\u1ea5t là g = 10 m\/s² và bán kính c\u1ee7a Trái \u0110\u1ea5t b\u1eb1ng R = 6400 km. Chu kì quay quanh Trái \u0110\u1ea5t c\u1ee7a v\u1ec7 tinh là<\/p>","options":["A.<\/strong> 2 gi\u1edd 48 phút.","B.<\/strong> 1 gi\u1edd 59 phút.","C.<\/strong> 3 gi\u1edd 57 phút.","D.<\/strong> 1 gi\u1edd 24 phút."],"correct":"2","level":"2","hint":"","answer":"Ch\u1ecdn B.<\/strong> 1 gi\u1edd 59 phút.<\/span><\/p>V\u1ec7 tinh chuy\u1ec3n \u0111\u1ed9ng tròn \u0111\u1ec1u quanh Trái \u0110\u1ea5t, l\u1ef1c h\u1ea5p d\u1eabn \u0111óng vai trò l\u1ef1c h\u01b0\u1edbng tâm nên gia t\u1ed1c h\u01b0\u1edbng tâm c\u0169ng chính là gia t\u1ed1c r\u01a1i t\u1ef1 do.<\/p>Gia t\u1ed1c: $a_{ht}=g=\\omega^2r=\\omega^2(R+R)=2R\\omega^2$<\/span> ⇒ $\\omega=\\sqrt{\\dfrac{g}{2R}}$<\/span>.<\/p>Chu kì quay quanh Trái \u0110\u1ea5t c\u1ee7a v\u1ec7 tinh là:<\/p>$T=\\dfrac{2\\pi}{\\omega}=\\dfrac{2\\pi\\sqrt{2R}}{\\sqrt{g}}=\\dfrac{2\\pi.\\sqrt{2.6400000}}{\\sqrt{10}}\\approx7109(s)\\approx$<\/span> 1 gi\u1edd 59 phút.<\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2025-04-13 15:02:59","option_type":"txt","len":2},{"id":"8325","mon_id":"1158790","chapter_id":"1159899","post_id":"8855","question":"\u0110\u1ec3 m\u1ed9t v\u1eadt có kh\u1ed1i l\u01b0\u1ee3ng b\u1eb1ng 12 kg chuy\u1ec3n \u0111\u1ed9ng tròn \u0111\u1ec1u trên qu\u1ef9 \u0111\u1ea1o có bán kính 0,4 m v\u1edbi t\u1ed1c \u0111\u1ed9 8 m\/s thì l\u1ef1c h\u01b0\u1edbng tâm ph\u1ea3i có \u0111\u1ed9 l\u1edbn g\u1ea7n nh\u1ea5t v\u1edbi giá tr\u1ecb nào sau \u0111ây?<\/p>","options":["A.<\/strong> 3,8.10³ N.","B.<\/strong> 9,6.10³ N.","C.<\/strong> 1,9.10³ N.","D.<\/strong> 1,8.10³ N."],"correct":"3","level":"2","hint":"","answer":"Ch\u1ecdn C.<\/strong> 1,9.10³ N.<\/span><\/p>L\u1ef1c h\u01b0\u1edbng tâm là $F_{ht}=\\dfrac{mv^2}{r}=\\dfrac{12.8^2}{0,4}=1920(N)$<\/span>.<\/p>V\u1eady l\u1ef1c h\u01b0\u1edbng tâm ph\u1ea3i có \u0111\u1ed9 l\u1edbn g\u1ea7n nh\u1ea5t v\u1edbi giá tr\u1ecb 1,9.10³ N.<\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2025-04-13 15:09:43","option_type":"txt","len":2},{"id":"8326","mon_id":"1158790","chapter_id":"1159899","post_id":"8855","question":"Trong chuy\u1ec3n \u0111\u1ed9ng tròn \u0111\u1ec1u, l\u1ef1c h\u01b0\u1edbng tâm<\/p>","options":["A.<\/strong> vuông góc v\u1edbi vect\u01a1 v\u1eadn t\u1ed1c.","B.<\/strong> cùng ph\u01b0\u01a1ng, cùng chi\u1ec1u v\u1edbi vect\u01a1 v\u1eadn t\u1ed1c.","C.<\/strong> cùng ph\u01b0\u01a1ng, ng\u01b0\u1ee3c chi\u1ec1u v\u1edbi vect\u01a1 v\u1eadn t\u1ed1c.","D.<\/strong> có h\u01b0\u1edbng không \u0111\u1ed5i."],"correct":"1","level":"2","hint":"L\u1ef1c h\u01b0\u1edbng tâm luôn cùng h\u01b0\u1edbng v\u1edbi vect\u01a1 gia t\u1ed1c h\u01b0\u1edbng tâm.<\/p>","answer":"Ch\u1ecdn A.<\/strong> vuông góc v\u1edbi vect\u01a1 v\u1eadn t\u1ed1c.<\/span><\/p>Trong chuy\u1ec3n \u0111\u1ed9ng tròn \u0111\u1ec1u, l\u1ef1c h\u01b0\u1edbng tâm vuông góc v\u1edbi vect\u01a1 v\u1eadn t\u1ed1c.<\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2025-04-13 15:12:17","option_type":"txt","len":3}]}