大家来做一道高一物理题

如图，A、B质量均为m,物体A与平面间动摩擦因数为u，滑轮与竖直面摩擦不计，若使A在水平面上作匀速直线运动，求施于A的水平力F是多大？

[此贴子已经被作者于2003-12-31 12:19:26编辑过]

展开全文

A所受摩擦力为umg B对A的拉力为mg 若使A匀速运动 则F=mg-umg

wrong~! B is moving at a certain rate, too. The line exerts a force of mg on B, so does that on A. In summary, the force exerted on A is mg. ---------------------------------------------------------------------------------------------------------------------- I know I am wrong. Sorry for that~

[此贴子已经被作者于2004-1-1 2:53:29编辑过]

儿子 请用汉语 我目前同意 飞龙在天

最好能把过程列一下 还有 儿子，建议你换个名字吧 这样让我很过意不去

Guys, you should try to use English when you study physics. Sorry for my first wrong answer. I've not beenkeeping in touch with physics for about a year since I have finished the one and a half year in PKU. It is not the situation as 飞龙在天 said, "A所受摩擦力为umg B对A的拉力为mg 若使A匀速运动 则F=mg-umg" In another condition, B might go up as well. So there is an alternative answer to this question: mg + umg

[此贴子已经被作者于2004-1-2 17:33:32编辑过]

However, it is much better to say "I don't think many people can speak or write English so well as you", I think. －－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－ i think many people don't speak or write english very well like you. ----------------------------------------------

i'm very sorry.i wrote this sentence by mistake. thank you for your help

我是不会了。

有两种情况。mg＋μmg，mg－μmg。