View Single Post
waynexk8
waynexk8 is offline
#229
Mar9-12, 07:34 PM
P: 399
Quote Quote by DaleSpam View Post
Ah, ok. That is a defined term in physics, called impulse:
http://en.wikipedia.org/wiki/Impulse_(physics)

Edit: I see sophiecentaur already mentioned it.

I just want to point out that impulse does not have units of force,
Interesting, so Impulse is something that changes the momentum/movement of an object; the integral, part of the whole of a force with respect to time, but if itís a part of force, is not it a force ???

This is what I keep saying; a small force applied for a long time can produce the same momentum/movement change as a large force applied briefly, because itís the product of the force and time for which it is applied that is important.

But this is my point, the small force is not applied longer then the large force, itís applied for the same time. So the small force applied for the same time as my large force for a brief time, canít not as we know cannot produce the same momentum/movement

Quote Quote by DaleSpam View Post
it has units of momentum. Assuming that we are talking about the impulse over one full rep then the change in momentum is 0 so the impulse on the weight is 0.

The only two forces acting on the weight are gravity and the human, so the impulse provided by the human is equal and opposite to the impulse provided by gravity. So, the impulse is equal to the weight times the duration of the rep. Therefore the human provides a larger impulse on a slow rep than on a fast rep.

waynekx8, if by "total force" you mean "impulse" then it is greater for a slow rep than for a fast rep. If you mean some other quantity then please define it explicitly.
No, as both are applied for the same time, the fast force {which is letís just call/say force now} is 100% force from the Man, or a 100 pounds of force moving the 80 pounds up 1m and down 1m for 6 times = 12m in 6 seconds. The slow force is 80% force from the Man, or 80 pounds of force moving the 100 pounds up 1m and down 1m 1 times = 2m in 6 seconds.

The fast uses 100 pounds of force for 6 seconds, and the slow uses 80 pounds of force for 6seconds. A 100 pounds of force = more than 80 pounds of force.


Wayne