题目内容
(10分)某同学设计了一个探究小车的加速度
与小车所受拉力
及质量
关系的实验,图(a)为实验装置简图.(所用交变电流的频率为
)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250016314738735.jpg)
①图(b)为某次实验得到的纸带,实验数据如图,图中相邻计数点之间还有4个点未画出,根据纸带可求出小车的加速度大小为
.(保留两位有效数字)
②保持砂和砂桶质量不变,改变小车质量
,分别得到小车加速度
与质量
及对应的
,数据如下表:
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/2014082500163172318739.jpg)
请在方格纸中画出
图线,并从图线可知小车加速度
与质量倒数
之间的关系是 .(填“线性”或“非线性”)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/2014082500163178534062.png)
③保持小车质量不变,改变砂和砂桶质量,一位同学根据实验数据作出了加速度
随拉力
的变化图线如图(c)所示。该图线不通过原点,其主要原因是 .
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825001631333283.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825001631348302.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825001631379337.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825001631457414.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250016314738735.jpg)
①图(b)为某次实验得到的纸带,实验数据如图,图中相邻计数点之间还有4个点未画出,根据纸带可求出小车的加速度大小为
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825001631489489.png)
②保持砂和砂桶质量不变,改变小车质量
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825001631379337.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825001631333283.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825001631379337.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825001631707382.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/2014082500163172318739.jpg)
请在方格纸中画出
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825001631738501.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825001631333283.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825001631707382.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/2014082500163178534062.png)
③保持小车质量不变,改变砂和砂桶质量,一位同学根据实验数据作出了加速度
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825001631333283.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825001631348302.png)
①0.51(3分) ②如图所示(2分),线性 (2分) ③没有平衡摩擦力(3分)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/2014082500163183215887.jpg)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/2014082500163183215887.jpg)
试题分析: ①相邻计数点之间还有4个点未画出,说明相邻的计数点时间间隔为
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825001631832471.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250016318631338.png)
②由表格可知小车的加速度与质量的倒数成正比,根据描点法画出图象,如上图所示;由
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825001631879602.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825001631333283.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825001631707382.png)
③从上图中发现直线没过原点,当F≠0时,a=0.也就是说当绳子上有拉力时小车的加速度还为0,说明小车的摩擦力与绳子的拉力抵消呢.该同学实验操作中遗漏了平衡摩擦力这个步骤。所以原因是没有平衡摩擦力或摩擦力平衡不够.
![](http://thumb2018.1010pic.com/images/loading.gif)
练习册系列答案
相关题目