题目内容
质量为2kg的物体置于水平面上,在运动方向上受拉力作用下沿水平面作匀变速运动,物体运动的速度图象如图所示。若物体受摩擦力为10N,则下列说法中正确的是
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408242031514271595.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408242031514271595.png)
A.拉力F做功150J |
B.拉力F做功100J |
C.摩擦力做功250 |
D.物体克服摩擦力做功250J |
AD
试题分析:从图像中可得物体的加速度为
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824203151879893.png)
根据牛顿第二定律可得:
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824203152940594.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824203154110531.png)
图像与坐标轴围成的面积表示位移,所以物体发生的位移为
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824203155202888.png)
故拉力做功为
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824203156341671.png)
摩擦力做功为
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824203157308810.png)
故选AD
点评:关键是知道图像的斜率以及面积表示的物理含义
![](http://thumb2018.1010pic.com/images/loading.gif)
练习册系列答案
相关题目