题目内容
一个质量为3kg的物体,在(0~4)s内受水平拉力F作用,在(4~10)s内仅受摩擦力作用而停止,其v-t图象如图所示,则物体所受的摩擦力是多少?水平拉力为多少?
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241156146221567.gif)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241156146221567.gif)
6; 15
物体在(0~4)s内,在水平拉力和摩擦力的共同作用下做匀加速直线运动,其加速度大小为
,则
;物体在(4~10)s内只受摩擦力作用,做匀减速运动,其加速度大小为
,则
,故f=
=3×2=6N,F-f=3×3=9N,F=15N.
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824115614638940.gif)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241156146541343.gif)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824115614654944.gif)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241156146691369.gif)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824115614685977.gif)
![](http://thumb2018.1010pic.com/images/loading.gif)
练习册系列答案
相关题目
题目内容