题目内容
有两个大小不变的共点力F1和F2,它们合力的大小F合随两力夹角的变化情况如图所示,则两力的大小分别为( )
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241321158161750.png)
图2-5-15
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241321158161750.png)
图2-5-15
A.8 N 4 N |
B.6 N 10 N |
C.2 N 10 N |
D.4 N 8 N |
AD
:选AD.由图可知:F1+F2=12①
|F1-F2|=4②
由①②代入数据解得
或![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824132115894911.png)
故A、D正确.
|F1-F2|=4②
由①②代入数据解得
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824132115847924.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824132115894911.png)
故A、D正确.
![](http://thumb2018.1010pic.com/images/loading.gif)
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