题目
题型:不详难度:来源:
A.20N | B.25N | C.30N | D.40N |
答案
F |
x |
20 |
2 |
当压缩时,F=kx=10×3N=30N,故ABD错误,C正确.
故选:C.
核心考点
举一反三
![](http://img.shitiku.com.cn/uploads/allimg/20191121/20191121193241-28315.png)
(1)弹簧的劲度系数k;
(2)物块与水平桌面之间的最大静摩擦力fm;
(3)物块与水平桌面之间的动摩擦因数μ.(g=10N/kg)
![](http://img.shitiku.com.cn/uploads/allimg/20191121/20191121193146-39890.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191121/20191121193130-83864.png)
实验测出了砝码的质量m与弹簧长度l的相应数据,如下表:(g=9.8m/s2)
A.20N | B.25N | C.30N | D.40N |
F |
x |
20 |
2 |