题目内容
B、C两个小球重量均为G,用细线悬挂在竖直墙上的A、D两点。细线与竖直墙壁之间的夹角分别为30o和60o (见图中标注),两个小球处于静止状态。求:
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250022250947115.png)
(1)AB和CD两根细线的拉力FAB和FCD 分别为多大?
(2)细线BC与竖直方向的夹角θ是多少?
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250022250947115.png)
(1)AB和CD两根细线的拉力FAB和FCD 分别为多大?
(2)细线BC与竖直方向的夹角θ是多少?
(1)
,
;(2)![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825002225172486.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825002225110656.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825002225126536.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825002225172486.png)
试题分析:(1)对两个小球构成的整体受力分析:(1分)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250022251883412.jpg)
在x、y轴方向正交分解,根据平衡条件可知
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825002225204929.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250022252191100.png)
联立可得:
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825002225110656.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825002225126536.png)
(2)对C球受力分析(1分)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250022252823319.jpg)
在x、y轴方向正交分解,根据平衡条件:
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825002225297938.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250022253131013.png)
联立解得:
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825002225172486.png)
![](http://thumb2018.1010pic.com/images/loading.gif)
练习册系列答案
相关题目