题目内容
有同学利用如图(甲)所示的装置来验证力的平行四边形定则。在竖直木板上铺有白纸,固定两个光滑的滑轮A和B,将绳子打一个结点O,在三段绳上分别挂上三组钩码,每个钩码的重量相等。当系统达到平衡时,根据钩码个数读出三根绳子的拉力,回答下列问题:
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408242302421424209.png)
(1)(多选题)改变钩码个数,实验能达到平衡的是:
A.钩码的个数![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824230243062657.png)
B.钩码的个数![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824230244216588.png)
C.钩码的个数![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824230245870710.png)
D.钩码的个数![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824230246666703.png)
(2)(多选题)达到平衡后,需要记录的是:
A.标记结点O的位置,并记录OA、OB、OC三段绳子的方向
B.量出OA、OB、OC三段绳子的长度
C.记下各组钩码的个数
D.用天平测出钩码的质量
(3)(单选题)该学生根据测量数据在白纸上画出了图(乙)
所示的五个力,以验证力的平行四边形定则,则:
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408242302476022519.png)
A.
是
的平衡力
B.
、
的合力是![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824230253077365.png)
C.
、
大小一定相等
D.
和
不重合,说明实验失败
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408242302421424209.png)
(1)(多选题)改变钩码个数,实验能达到平衡的是:
A.钩码的个数
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824230243062657.png)
B.钩码的个数
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824230244216588.png)
C.钩码的个数
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824230245870710.png)
D.钩码的个数
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824230246666703.png)
(2)(多选题)达到平衡后,需要记录的是:
A.标记结点O的位置,并记录OA、OB、OC三段绳子的方向
B.量出OA、OB、OC三段绳子的长度
C.记下各组钩码的个数
D.用天平测出钩码的质量
(3)(单选题)该学生根据测量数据在白纸上画出了图(乙)
所示的五个力,以验证力的平行四边形定则,则:
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408242302476022519.png)
A.
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824230248475384.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824230249505366.png)
B.
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824230250815371.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824230251689384.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824230253077365.png)
C.
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824230254310343.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824230255667358.png)
D.
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824230256618369.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824230257476374.png)
(1)BC(2)AC(3)A
试题分析:(1)A中由于OA和OB绳不能和OC绳共线,虽然N1+N2=N3,所以系统也不能平衡;B中
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824230244216588.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824230245870710.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824230246666703.png)
(3)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824230248475384.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824230249505366.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824230250815371.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824230251689384.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824230305495375.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824230254310343.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824230255667358.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824230256618369.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824230257476374.png)
![](http://thumb2018.1010pic.com/images/loading.gif)
练习册系列答案
相关题目