Re: "Dissipation" (was Re: momentum conservation(2))

[Tim Burgess <tburgess@JAGUAR1.USOUTHAL.EDU>]

On Wed, 15 Mar 2000, John Mallinckrodt wrote:
> Velcro in its intended use does not store any significant amount of
> potential energy.  When two carts equipped with velcro collide, the "lost"
> kinetic energy is indeed *dissipated*, not transformed into potential
> energy of bent velcro barbs.  If you find that the cart is launched with a
> small velocity after being torn free, it is simply because you were
> exerting a force on it in order to tear it free and *kept* exerting that
> force for a short time *after* it broke free.

After a nights sleep and a reread I agree that the launching force is
provided by the hand shortly after breaking free. Whoops!  The size
of this initial force may be related to the nature of the velcro and
number of barbs hooked etc.... but the work is being done by the hand!


Tim Burgess