题目内容
甲,乙两物体都做匀速圆周运动,若m甲:m乙=1:2,R甲:R乙=1:2,T甲:T乙=3:4,则它们所需的向心力F甲:F乙应为:( )
A.1::4 | B.2:3 | C.4:9 | D.9:16 |
C
本题考查匀速圆周运动
设甲,乙两物体做匀速圆周运动的角速度分别为
,则T甲:T乙=3:4得
;
又R甲:R乙=1:2,m甲:m乙=1:2,
由向心力公式有![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824121157847904.png)
则![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241211578631851.png)
即![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824121157941572.png)
故正确答案为C
设甲,乙两物体做匀速圆周运动的角速度分别为
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824121157753416.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824121157800537.png)
又R甲:R乙=1:2,m甲:m乙=1:2,
由向心力公式有
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824121157847904.png)
则
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241211578631851.png)
即
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824121157941572.png)
故正确答案为C
![](http://thumb2018.1010pic.com/images/loading.gif)
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