题目内容
如图,一半圆形碗的边缘上装有一定滑轮,滑轮两边通过一不可伸长的轻质细线挂着两个小物体,质量分别为m1、m2, m1>m2。现让m1从靠近定滑轮处由静止开始沿碗内壁下滑。设碗固定不动,其内壁光滑、半径为R。则m1滑到碗最低点时的速度为
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250041485763645.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250041485763645.png)
A.![]() | B.![]() | C.![]() | D.![]() |
D
试题分析:设m1到达最低点时,m2的速度为v,m1的速度沿绳子方向的分速度等于m2的速度则到达最低点时m1的速度v′=
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825004148669598.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825004148685427.png)
根据系统机械能守恒有:m1gR-m2g.
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825004148700435.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825004148716338.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825004148716338.png)
又v′=
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825004148685427.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250041486541131.png)
![](http://thumb2018.1010pic.com/images/loading.gif)
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