题目内容
如图所示,A、B两球完全相同,质量均为
,用两根等长的细线悬挂在升降机内天花板的O点,两球之间连着一根劲度系数为七的轻质弹簧,当升降机以加速度
竖直向上匀加速运动时,两根细线之间的夹角为
。则弹簧的被压缩的长度为
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/2014082413130026513108.png)
A.
B.![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824131300499726.png)
C.![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824131300874169.png)
D.![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241313011081104.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824131259688339.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824131259875285.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824131259907299.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/2014082413130026513108.png)
A.
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824131300468896.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824131300499726.png)
C.
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824131300874169.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241313010771068.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241313011081104.png)
C
设每根绳子的拉力为T,弹簧的弹力为F,对B球受力分析:
Tsin
-mg=ma, Tcos
=F, F=KX
联立,解得K=![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241313010771068.png)
Tsin
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824131301451414.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824131301451414.png)
联立,解得K=
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241313010771068.png)
![](http://thumb2018.1010pic.com/images/loading.gif)
练习册系列答案
相关题目