题目内容
某物体以40 m/s的初速度竖直上抛,不计空气阻力,g取10 m/s2,则抛出后5s内物体的( )
A.速度改变量的大小为45 m/s | B.平均速度大小为15m/s,方向向上 |
C.位移大小为75m,方向向下 | D.路程为85 m |
BD
试题分析:由
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824155843161512.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824155843224563.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241558433481040.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824155843426744.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241558435361110.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824155843707815.png)
点评:本题难度中等,处理竖直上抛运动,可分段求解也可看做整体过程的匀减速直线运动求解,一定要注意规定正方向
![](http://thumb2018.1010pic.com/images/loading.gif)
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