题目内容
(6分)用图甲所示的装置利用打点计时器进行探究动能定理的实验,实验时测得小车的质量为
,木板的倾角为
。实验过程中,选出一条比较清晰的纸带,用直尺测得各点与A点间的距离如图乙所示:AB=
;AC=
;AD=
;AE=
。已知打点计时器打点的周期为T,重力加速度为g,小车与斜面间摩擦可忽略不计。那么打D点时小车的瞬时速度为 ;取纸带上的BD段进行研究,合外力做的功为 ,小车动能的改变量为 。
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250032514207117.jpg)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825003251295337.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825003251311297.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825003251326342.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825003251357388.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825003251373375.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825003251389368.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250032514207117.jpg)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250032514511715.png)
试题分析:匀变速直线运动的平均速度等于中间时刻瞬时速度,因此有:
vD=
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825003251467649.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825003251482633.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825003251513338.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825003251529396.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825003251513338.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825003251560391.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825003251591959.png)
重力做功为:W=mg(d3-d1)sinθ。
![](http://thumb2018.1010pic.com/images/loading.gif)
练习册系列答案
相关题目