View Single Post
Old 09-20-2009, 06:53 PM   #2
Andoror

Join Date
Oct 2005
Posts
647
Senior Member
Default
The example works for massless gremlins capable of exerting force in a vacuum (rocket packs?).

I was being fantastic. The problem I seem to be having is understanding dynamic equilibrium in ordinary circumstances.


A simpler way to understand the crate example would be to ponder the answer to this question: when you're pushing a crate so that it moves with a fixed speed, you still have to keep pushing it in order for it to move at that fixed speed, don't you?

But in order to set the crate in motion you have to overcome any opposing forces, how can those opposing forces be equal if the object is in motion?

If the opposing forces, your push and friction, are not equal then the crate is not in equilibrium.

If the forces are equal then the crate won't move.
Andoror is offline


 

All times are GMT +1. The time now is 11:26 PM.
Copyright ©2000 - 2012, Jelsoft Enterprises Ltd.
Design & Developed by Amodity.com
Copyright© Amodity