题目内容
如图所示在水平地面上放置质量均为
=400g的木块A和B,一质量为
=50g的子弹以水平速度
=100m/s射入木块A,当子弹穿出A时,速度
=80m/s,子弹未穿出木块B,若木块与地面间的动摩擦因数均为μ=0.2,求子弹射入B后,B木块在地面上前进的距离.
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824115554857319.gif)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824115554873195.gif)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824115554888195.gif)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824115554904191.gif)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241155549352054.jpg)
s=25m
对整体,根据动量守恒定律
Mv0=mv1+2Mv2,得v2=1.25m/s
对m和B,根据动量守恒定律mv1+Mv2=(M+m)v,得v=10m/s
对m和B,根据动能定理
,得s=25m
Mv0=mv1+2Mv2,得v2=1.25m/s
对m和B,根据动量守恒定律mv1+Mv2=(M+m)v,得v=10m/s
对m和B,根据动能定理
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824115554935771.gif)
![](http://thumb2018.1010pic.com/images/loading.gif)
练习册系列答案
相关题目