作者dreamseeker1 (思考者)
看板Physics
标题[请益] goldstein力学一段
时间Thu May 31 21:08:52 2007
p.17
Note that if a particle is constrained to the surface and that is itself
moving in time, the force of constraint is instantaneously perpendicular to
the surface and the work during a virtual displacement is still zero even
though the work during an actual displacement in the time dt does not
necessarily vanish.
疑问
1. 第一句是在说质点被限制在一个本身会移动的面上吗？
这样跟假设点在面上移动有什麽不一样呢？
2.既然力都垂直於表面,那为什麽actual displacement 中的work有可能不为0呢?
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