大家来做一道高一物理题 -

标题: 大家来做一道高一物理题 [打印本页]

作者: 快乐一点点 时间: 03-12-31 12:18
标题: 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]

作者: 飞龙在天 时间: 03-12-31 15:12
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

作者: 儿子 时间: 03-12-31 17:03
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]

作者: JORDAN 时间: 03-12-31 20:17
儿子请用汉语我目前同意飞龙在天

作者: 快乐一点点 时间: 03-12-31 21:48
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

作者: 儿子 时间: 04-1-1 02:40
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]

作者: 儿子 时间: 04-1-1 15:26
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. ----------------------------------------------

作者: 荩予 时间: 04-1-1 17:17
i'm very sorry.i wrote this sentence by mistake. thank you for your help

作者: 怪才墨雨 时间: 04-1-2 11:20
我是不会了。

作者: AK47 时间: 04-1-3 19:03
有两种情况。mg＋μmg，mg－μmg。

作者: JORDAN 时间: 04-1-4 13:06
哦

作者: 莹莹晶晶 时间: 04-4-11 18:46

没错，是两种情况～

摩擦力可能向左也可能向右。

作者: 寒声碎 时间: 04-4-18 13:20

以下是引用AK47在2004-1-3 19:03:56的发言： 有两种情况。mg＋μmg，mg－μmg。

对，我还差点忽略了第一种情况。嘿嘿，还物理班呢我

作者: 阳光晨 时间: 04-4-18 22:15
同意AK47的.两种情况.

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