题目内容
质量为
的物体M以
的初动能在粗糙的水平面上沿直线滑行,M的动能随其位置坐标的变化关系如图所示,据此可知物体滑行的时间为:
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408242055089085019.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824205506631465.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824205507676408.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408242055089085019.png)
A.![]() | B.![]() | C.![]() | D.![]() |
C
试题分析:根据动能定理得:
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824205513105609.png)
结合动能随位移变化的情况得:初动能EK1=50J,初速度v=
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824205514134365.png)
从斜率可知f=5N,由于
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824205515289639.png)
t=
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824205516350373.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824205516989379.png)
故选C.
点评:利用数学图象处理物理问题的方法就是把物理表达式与图像结合起来,根据图像中的数据求解.一般我们通过图像的特殊值和斜率进行求解
![](http://thumb2018.1010pic.com/images/loading.gif)
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