[Phys-L] Re: collision question

[Carl Mungan <mungan@USNA.EDU>]

> Looking at the collision in this context, I
> am still lacking a coherent, straightforward
> explanation (for HS students) why there are several
> mechanisms for CoM KE to diminish but these same
> mechanisms (which for the most part involve vibrating
> particles) do not result in a reduction of CoM
> momentum.

To repeat Bob's good answers to this interesting question in another
way: There is only one "kind" of momentum, but there are many "kinds"
of energy. This realization is important because we need to compare
momentum not to KE (which is NOT a conserved quantity) but to energy
(which is). Carl
--
Carl E. Mungan, Asst. Prof. of Physics  410-293-6680 (O) -3729 (F)
       U.S. Naval Academy, Stop 9C, Annapolis, MD 21402-5040
mailto:mungan@usna.edu       http://usna.edu/Users/physics/mungan/