Tác dụng làm quay của lực. Momen lực

Home Lớp 8 Khoa học tự nhiên 8 - sách Kết nối tri thức Bài 18: Tác dụng làm quay của lực. Momen lựcBài tập cơ bản

{"common":{"save":0,"post_id":"8844","level":1,"total":10,"point":10,"point_extra":0},"segment":[{"id":"9159","post_id":"8844","mon_id":"1159539","chapter_id":"1159793","question":"Ch\u1ecdn t\u1eeb thích h\u1ee3p \u0111i\u1ec1n vào ch\u1ed7 tr\u1ed1ng: L\u1ef1c tác d\u1ee5ng lên m\u1ed9t v\u1eadt có th\u1ec3 làm _________ v\u1eadt quanh m\u1ed9t tr\u1ee5c hay m\u1ed9t \u0111i\u1ec3m c\u1ed1 \u0111\u1ecbnh.<\/p>","options":["A.<\/strong> quay.<\/p>","B.<\/strong> \u0111\u1ee9ng yên.<\/p>","C.<\/strong> bi\u1ebfn \u0111\u1ed5i.<\/p>","D.<\/strong> thay \u0111\u1ed5i.<\/p>"],"correct":"1","level":"1","hint":"Ki\u1ebfn th\u1ee9c v\u1ec1 tác d\u1ee5ng làm quay c\u1ee7a l\u1ef1c.<\/p>","answer":"\u0110áp án \u0111úng là:<\/strong> A. quay. Gi\u1ea3i thích:<\/em><\/p>Khi l\u1ef1c không \u0111i qua tr\u1ee5c quay thì có th\u1ec3 làm v\u1eadt quay quanh tr\u1ee5c ho\u1eb7c \u0111i\u1ec3m c\u1ed1 \u0111\u1ecbnh. \u0110ây là tác d\u1ee5ng làm quay c\u1ee7a l\u1ef1c.<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"132","test":"0","date":"2025-04-13 22:05:26","option_type":"txt","len":2},{"id":"9160","post_id":"8844","mon_id":"1159539","chapter_id":"1159793","question":"Ch\u1ecdn t\u1eeb thích h\u1ee3p \u0111i\u1ec1n vào ch\u1ed7 tr\u1ed1ng: Tác d\u1ee5ng làm quay c\u1ee7a l\u1ef1c ph\u1ee5 thu\u1ed9c vào \u0111i\u1ec3m \u0111\u1eb7t, _______ và h\u01b0\u1edbng c\u1ee7a l\u1ef1c.<\/p>","options":["A.<\/strong> \u0111\u1ed9 th\u1eb3ng.<\/p>","B.<\/strong> \u0111\u1ed9 to.<\/p>","C.<\/strong> \u0111\u1ed9 l\u1edbn.<\/p>","D.<\/strong> \u0111\u1ed9 nh\u1ecf.<\/p>"],"correct":"3","level":"1","hint":"Ki\u1ebfn th\u1ee9c c\u01a1 b\u1ea3n v\u1ec1 y\u1ebfu t\u1ed1 \u1ea3nh h\u01b0\u1edfng \u0111\u1ebfn moment l\u1ef1c.<\/p>","answer":"\u0110áp án \u0111úng là: C.<\/strong> \u0111\u1ed9 l\u1edbn.<\/p>Gi\u1ea3i thích:<\/em><\/p>Tác d\u1ee5ng làm quay c\u1ee7a l\u1ef1c ph\u1ee5 thu\u1ed9c vào v\u1ecb trí \u0111\u1eb7t l\u1ef1c, h\u01b0\u1edbng c\u1ee7a l\u1ef1c và \u0111\u1ed9 l\u1edbn c\u1ee7a l\u1ef1c tác d\u1ee5ng.<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"132","test":"0","date":"2025-04-13 22:07:11","option_type":"txt","len":1},{"id":"9161","post_id":"8844","mon_id":"1159539","chapter_id":"1159793","question":"Ch\u1ecdn t\u1eeb thích h\u1ee3p \u0111i\u1ec1n vào ch\u1ed7 tr\u1ed1ng: Tác d\u1ee5ng làm quay c\u1ee7a l\u1ef1c lên m\u1ed9t v\u1eadt quay quanh m\u1ed9t tr\u1ee5c hay m\u1ed9t \u0111i\u1ec3m c\u1ed1 \u0111\u1ecbnh \u0111\u01b0\u1ee3c \u0111\u1eb7c tr\u01b0ng b\u1eb1ng ________.<\/p>","options":["A.<\/strong> l\u1ef1c ma sát.<\/p>","B.<\/strong> moment l\u1ef1c.<\/p>","C.<\/strong> l\u1ef1c \u0111\u1ea9y.<\/p>","D.<\/strong> l\u1ef1c hút.<\/p>"],"correct":"2","level":"1","hint":"\u0110\u1ecbnh ngh\u0129a v\u1ec1 moment l\u1ef1c trong bài h\u1ecdc.<\/p>","answer":"\u0110áp án \u0111úng là: B.<\/strong> moment l\u1ef1c.<\/p>Gi\u1ea3i thích:<\/em><\/p>Moment l\u1ef1c \u0111\u1eb7c tr\u01b0ng cho m\u1ee9c \u0111\u1ed9 tác d\u1ee5ng làm quay c\u1ee7a l\u1ef1c \u0111\u1ed1i v\u1edbi v\u1eadt quanh m\u1ed9t tr\u1ee5c quay.<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"132","test":"0","date":"2025-04-13 22:08:37","option_type":"txt","len":2},{"id":"9162","post_id":"8844","mon_id":"1159539","chapter_id":"1159793","question":"Ch\u1ecdn t\u1eeb thích h\u1ee3p \u0111i\u1ec1n vào ch\u1ed7 tr\u1ed1ng: L\u1ef1c càng l\u1edbn thì moment l\u1ef1c càng ________, tác d\u1ee5ng l\u1ef1c quay càng l\u1edbn.<\/p>","options":["A.<\/strong> nh\u1ecf.<\/p>","B.<\/strong> l\u1edbn.<\/p>","C.<\/strong> b\u1eb1ng nhau.<\/p>","D.<\/strong> kém h\u01a1n.<\/p>"],"correct":"2","level":"1","hint":"Xét công th\u1ee9c tính moment l\u1ef1c $M=F.d$<\/span><\/p>","answer":"\u0110áp án \u0111úng là: B.<\/strong> l\u1edbn.<\/p>Gi\u1ea3i thích:<\/em><\/p>Khi \u0111\u1ed9 l\u1edbn l\u1ef1c t\u0103ng (v\u1edbi cùng cánh tay \u0111òn), thì moment l\u1ef1c c\u0169ng t\u0103ng → tác d\u1ee5ng quay t\u0103ng.<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"132","test":"0","date":"2025-04-13 22:10:38","option_type":"txt","len":2},{"id":"9163","post_id":"8844","mon_id":"1159539","chapter_id":"1159793","question":"Ch\u1ecdn t\u1eeb thích h\u1ee3p \u0111i\u1ec1n vào ch\u1ed7 tr\u1ed1ng: Giá c\u1ee7a l\u1ef1c càng ___________ tr\u1ee5c quay, moment l\u1ef1c càng l\u1edbn, tác d\u1ee5ng làm quay càng l\u1edbn.<\/p>","options":["A.<\/strong> xa.<\/p>","B.<\/strong> g\u1ea7n.<\/p>","C.<\/strong> nh\u1ecf.<\/p>","D.<\/strong> l\u1edbn.<\/p>"],"correct":"1","level":"1","hint":"Công th\u1ee9c moment l\u1ef1c ph\u1ee5 thu\u1ed9c vào kho\u1ea3ng cách \u0111\u1ebfn tr\u1ee5c quay.<\/p>","answer":"\u0110áp án \u0111úng là: A.<\/strong> xa.<\/p>Gi\u1ea3i thích:<\/em><\/p>Cánh tay \u0111òn dài h\u01a1n s\u1ebd t\u1ea1o moment l\u1ef1c l\u1edbn h\u01a1n, do \u0111ó tác d\u1ee5ng quay m\u1ea1nh h\u01a1n.<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"132","test":"0","date":"2025-04-13 22:12:35","option_type":"txt","len":0},{"id":"9164","post_id":"8844","mon_id":"1159539","chapter_id":"1159793","question":"Ch\u1ecdn t\u1eeb thích h\u1ee3p \u0111i\u1ec1n vào ch\u1ed7 tr\u1ed1ng: Giá c\u1ee7a l\u1ef1c càng xa tr\u1ee5c quay, moment l\u1ef1c càng ______, tác d\u1ee5ng làm quay càng l\u1edbn.<\/p>","options":["A.<\/strong> nh\u1ecf.<\/p>","B.<\/strong> l\u1edbn.<\/p>","C.<\/strong> b\u1eb1ng nhau.<\/p>","D.<\/strong> kém h\u01a1n.<\/p>"],"correct":"2","level":"1","hint":"Moment l\u1ef1c t\u0103ng khi kho\u1ea3ng cách \u0111\u1ebfn tr\u1ee5c quay t\u0103ng.<\/p>","answer":"\u0110áp án \u0111úng là: B.<\/strong> l\u1edbn.<\/p>Gi\u1ea3i thích:<\/em><\/p>Càng tác d\u1ee5ng l\u1ef1c xa tr\u1ee5c quay thì moment l\u1ef1c càng l\u1edbn, t\u1eeb \u0111ó hi\u1ec7u qu\u1ea3 quay càng cao.<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"132","test":"0","date":"2025-04-15 18:19:59","option_type":"txt","len":2},{"id":"9165","post_id":"8844","mon_id":"1159539","chapter_id":"1159793","question":"\u0110\u1ea1i l\u01b0\u1ee3ng \u0111\u1eb7c tr\u01b0ng cho tác d\u1ee5ng làm quay c\u1ee7a l\u1ef1c g\u1ecdi là gì?<\/p>","options":["A.<\/strong> Tr\u1ecdng l\u1ef1c.<\/p>","B.<\/strong> Ma sát.<\/p>","C.<\/strong> Moment l\u1ef1c.<\/p>","D.<\/strong> Áp su\u1ea5t.<\/p>"],"correct":"3","level":"1","hint":"\u0110\u1ea1i l\u01b0\u1ee3ng này ph\u1ee5 thu\u1ed9c vào \u0111\u1ed9 l\u1edbn c\u1ee7a l\u1ef1c và kho\u1ea3ng cách t\u1eeb tr\u1ee5c quay \u0111\u1ebfn giá c\u1ee7a l\u1ef1c.<\/p>","answer":"\u0110áp án \u0111úng là: C.<\/strong> Moment l\u1ef1c.<\/p>Gi\u1ea3i thích:<\/em><\/p>Moment l\u1ef1c \u0111\u1eb7c tr\u01b0ng cho m\u1ee9c \u0111\u1ed9 làm quay c\u1ee7a l\u1ef1c \u0111\u1ed1i v\u1edbi v\u1eadt quanh m\u1ed9t \u0111i\u1ec3m ho\u1eb7c tr\u1ee5c c\u1ed1 \u0111\u1ecbnh.<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"132","test":"0","date":"2025-04-15 18:22:53","option_type":"txt","len":2},{"id":"9166","post_id":"8844","mon_id":"1159539","chapter_id":"1159793","question":"\u0110\u01a1n v\u1ecb c\u1ee7a moment l\u1ef1c trong h\u1ec7 SI là gì?<\/p>","options":["A.<\/strong> Niut\u01a1n (N)<\/p>","B.<\/strong> Mét (m)<\/p>","C.<\/strong> Niut\u01a1n nhân mét (N.m)<\/p>","D.<\/strong> Kilôgam (kg)<\/p>"],"correct":"3","level":"1","hint":"Moment l\u1ef1c là tích c\u1ee7a l\u1ef1c và \u0111\u1ed9 dài cánh tay \u0111òn.<\/p>","answer":"\u0110áp án \u0111úng là: C.<\/strong> Niut\u01a1n nhân mét (N.m)<\/p>Gi\u1ea3i thích:<\/em><\/p>Vì moment l\u1ef1c \u0111\u01b0\u1ee3c tính b\u1eb1ng công th\u1ee9c $M=F.d$<\/span>, nên \u0111\u01a1n v\u1ecb là $N.m$<\/span>.<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"132","test":"0","date":"2025-04-15 18:24:50","option_type":"txt","len":2},{"id":"9167","post_id":"8844","mon_id":"1159539","chapter_id":"1159793","question":"Trong bi\u1ec3u th\u1ee9c tính moment l\u1ef1c $M=F.d$<\/span>, \u0111\u1ea1i l\u01b0\u1ee3ng $d$<\/span> là gì?<\/p>","options":["A.<\/strong> Kho\u1ea3ng cách t\u1eeb \u0111i\u1ec3m \u0111\u1eb7t l\u1ef1c \u0111\u1ebfn v\u1eadt.<\/p>","B.<\/strong> Kho\u1ea3ng cách t\u1eeb giá c\u1ee7a l\u1ef1c \u0111\u1ebfn tr\u1ee5c quay.<\/p>","C.<\/strong> Chi\u1ec1u dài c\u1ee7a l\u1ef1c tác d\u1ee5ng.<\/p>","D.<\/strong> Kho\u1ea3ng cách t\u1eeb l\u1ef1c \u0111\u1ebfn \u0111i\u1ec3m t\u1ef1a.<\/p>"],"correct":"2","level":"1","hint":"\u0110ây là \u0111\u1ed9 dài vuông góc t\u1eeb tr\u1ee5c quay \u0111\u1ebfn giá c\u1ee7a l\u1ef1c.<\/p>","answer":"\u0110áp án \u0111úng là: B.<\/strong> Kho\u1ea3ng cách t\u1eeb giá c\u1ee7a l\u1ef1c \u0111\u1ebfn tr\u1ee5c quay.<\/p>Gi\u1ea3i thích:<\/em><\/p>Cánh tay \u0111òn là kho\u1ea3ng cách t\u1eeb tr\u1ee5c quay \u0111\u1ebfn giá c\u1ee7a l\u1ef1c, vuông góc v\u1edbi l\u1ef1c.<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"132","test":"0","date":"2025-04-15 18:27:26","option_type":"txt","len":3},{"id":"9168","post_id":"8844","mon_id":"1159539","chapter_id":"1159793","question":"Khi tác d\u1ee5ng cùng m\u1ed9t l\u1ef1c vào v\u1eadt, mu\u1ed1n t\u0103ng moment l\u1ef1c thì c\u1ea7n:<\/p>","options":["A.<\/strong> T\u0103ng kh\u1ed1i l\u01b0\u1ee3ng c\u1ee7a v\u1eadt.<\/p>","B.<\/strong> Gi\u1ea3m chi\u1ec1u dài v\u1eadt.<\/p>","C.<\/strong> T\u0103ng kho\u1ea3ng cách t\u1eeb tr\u1ee5c quay \u0111\u1ebfn giá c\u1ee7a l\u1ef1c.<\/p>","D.<\/strong> \u0110\u1ed5i h\u01b0\u1edbng l\u1ef1c.<\/p>"],"correct":"3","level":"1","hint":"Xét y\u1ebfu t\u1ed1 làm t\u0103ng moment l\u1ef1c theo công th\u1ee9c $M=F.d$<\/span>.<\/p>","answer":"\u0110áp án \u0111úng là: C.<\/strong> T\u0103ng kho\u1ea3ng cách t\u1eeb tr\u1ee5c quay \u0111\u1ebfn giá c\u1ee7a l\u1ef1c.<\/p>Gi\u1ea3i thích:<\/em><\/p>V\u1edbi l\u1ef1c không \u0111\u1ed5i, mu\u1ed1n moment l\u1ef1c l\u1edbn h\u01a1n thì c\u1ea7n t\u0103ng \u0111\u1ed9 dài cánh tay \u0111òn, t\u1ee9c là t\u0103ng kho\u1ea3ng cách t\u1eeb tr\u1ee5c quay \u0111\u1ebfn giá c\u1ee7a l\u1ef1c.<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"132","test":"0","date":"2025-04-15 18:29:13","option_type":"txt","len":3}]}