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-   -   Force exerted over a small time and big time frame (http://www.physicsforums.com/showthread.php?t=669809)

Howlin Feb6-13 09:25 AM

Force exerted over a small time and big time frame
 
Hi

Why is it that if you hit an object fast it requires less force to break it than if you hit the object slow and applied pressure to it?

A.T. Feb6-13 09:37 AM

Re: Force exerted over a small time and big time frame
 
If you hit it fast, the forces are higher.

Howlin Feb6-13 10:13 AM

Re: Force exerted over a small time and big time frame
 
So you are saying if I hit a block of wood or glass really fast, it takes the same force to break it than if i use a force press and it slowly applies force to the block of wood or glass?

russ_watters Feb6-13 10:20 AM

Re: Force exerted over a small time and big time frame
 
No, he said HIGHER.

However, it may take less impulse (force times time).

Howlin Feb6-13 10:23 AM

Re: Force exerted over a small time and big time frame
 
Quote:

Quote by russ_watters (Post 4259478)
No, he said HIGHER.

However, it may take less impulse (force times time).

But why would it be higher, shouldn't it be just the same force required to break the boards or glass, no matter if it is hit fast or slow?

russ_watters Feb6-13 10:29 AM

Re: Force exerted over a small time and big time frame
 
When you apply a force, the object moves - even when holding it rigidly, it bends. The faster you apply the force, the more of the force that is absorbed by the acceleration of the object.

A.T. Feb6-13 02:39 PM

Re: Force exerted over a small time and big time frame
 
Quote:

Quote by Howlin (Post 4259483)
But why would it be higher, shouldn't it be just the same force required to break the boards or glass, no matter if it is hit fast or slow?

The peak contact force is higher not the force required to break .


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