Re: CONSERVATION OF ENERGY

[LUDWIK KOWALSKI <kowalskil@alpha.montclair.edu>]

On 12 Jul 97 David Dockstader <DRDOCK00@UKCC.UKY.EDU> wrote:

> Without knowing what Ludwik is driving at, people can read into his
> question anything they want.  

OK, I could have added that very small fractions of K, which may possibly 
go into sound, electromagnetic radiation, permament deformation (scratches), 
chemical transformations, etc., can be ignored. If all the initial kinetic 
energy of the cube goes into the thermal energy, dU, then how can we say 
that "work done through friction (in the described situation) is due to K"? 
What does it mean that "energy is an ability to do work"? And I am asking 
these questions as a teacher of an introductory physics course. Suppose we
know that K=10 J. Would the experimentally determined dU=c*(m+M)*dT be
very close to 10 J?
                                              Ludwik Kowalski