题目内容
(14分)质量为2kg的物体在水平推力F的作用下沿水平面作直线运动,一段时间后撤去F,其运动的v-t图像如图所示。g取10m/s2,求:
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250048402605026.jpg)
(1)物体与水平面间的运动摩擦因数;
(2)水平推力F的大小;
(3)0—10s内物体运动位移的大小。
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250048402605026.jpg)
(1)物体与水平面间的运动摩擦因数;
(2)水平推力F的大小;
(3)0—10s内物体运动位移的大小。
(1)
(2)
(3)![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825004840323524.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825004840276474.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825004840291518.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825004840323524.png)
试题分析:(1)由v-t图像,可知物体做匀加速直线运动的加速度
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825004840338584.png)
物体做匀减速直线运动的加速度
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825004840354619.png)
根据牛顿第二定律,有:
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825004840369662.png)
解得:
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825004840276474.png)
(2)物体做匀加速直线运动时,根据牛顿第二定律,有:
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825004840401716.png)
解得:
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825004840291518.png)
(3)由匀变速直线运动位移公式,得
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250048404321317.png)
![](http://thumb2018.1010pic.com/images/loading.gif)
练习册系列答案
相关题目