小华往墙上按图钉.已知图钉帽的面积是1cm2,图钉尖的面积是5×10-4cm2,手指对图钉
人气:464 ℃ 时间:2019-08-26 03:36:44
解答
小华往墙上按图钉.已知图钉帽的面积是1cm^2,图钉尖的面积是5×10-4cm^2,手指对图钉帽的压力是20N,求图钉尖对墙的压强和手对图钉帽的压强.
5×10^-4cm^2=m^2
1cm^2=10^-4m^2
图钉尖对墙的压强:20/(5×10^-8)=4×10^8 Pa
手对图钉帽的压强20/(10^-4)=2×10^5Pa
推荐
- 小华往墙上按图钉时,图钉帽的面积为1cm2,图钉尖的面积为5×10-4cm2,手指对图钉帽的压力是40N,求:图钉尖对墙的压强是手对图钉帽压强的多少倍?
- 向墙上按图钉,已知图钉帽的面积为1cm2,图钉尖的面积是0.05mm2,手指对图钉帽的压力与图钉尖对墙的压力之比为_,压强之比_.
- 一颗图钉尖的面积是5×10-8m2,图钉帽的面积是0.5×10-4m2,手指对图钉的压力为20N,求:
- 要把图钉按入墙壁,压强至少达到8x10^8帕,若图钉帽的面积为1cm2,图钉尖的面积为0.05毫米2,则手指对钉帽
- 一颗图钉尖的面积是5×10-8m2,图钉帽的面积是0.5×10-4m2,手指对图钉的压力为20N,求:
- Hao come I din't know you went shopping?
- The old man ( ) ( ) when he was ( ) the road.那位老人过马路时摔倒了.
- 函数f(x)对一切实数x都满足f(0.5+x)=f(0.5-x),并且方程f(x)=0有三个实根.则这3个实根的和为?
猜你喜欢