题目内容
如图所示装置中,两物体的质量分别为m1、m2,轻绳先后绕过挂有m1的动滑轮和定滑轮b,悬点a与定滑轮b左边缘间的距离大于动滑轮的直径,不计一切摩擦,若装置处于静止状态,则
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241543510891833.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241543510891833.png)
A.m2可以大于m1 | B.m2一定大于![]() |
C.m2可能等于![]() | D.θ1一定等于θ2 |
ABD
试题分析:对
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824154351526325.png)
对
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824154351526325.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824154351526325.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824154352181414.png)
对于滑轮分析,由于滑轮跨在绳子上,故两端绳子的拉力相等,它们的合力一定在角平分线上;由于它们的合力与
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824154352290295.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824154352415330.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824154352493358.png)
由以上可知,两端绳子的拉力等于
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824154352181414.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824154352634399.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824154352696612.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824154352758684.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824154352181414.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824154352634399.png)
故选ABD.
点评:本题要注意题目中隐含的信息,记住同一绳子各部分的张力相等,即可由几何关系得出夹角的关系;同时还要注意应用力的合成的一些结论.
![](http://thumb2018.1010pic.com/images/loading.gif)
练习册系列答案
相关题目