Re: CONSERVATION OF ENERGY

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

Date: Sat, 26 Jul 1997 00:13:18 -0400
From: Bob Sciamanda <Sciamanda@worldnet.att.net>

> The Work-Energy Theorem of Newtonian Mechanics [should not be] confused 
> with the First Law of Thermodynamics.  Given the situation (as I read you): 
> R is the constant net force on the object as it "loses" K (kinetic energy) 
> over a displacement x (in the direction of R), then K and R*x are numerically 
> equal - and rigorously so, by Newton's laws of motion. This is a purely 
> mechanical (dynamics) question, and stands quite apart from any conservation 
> of energy postulate or thermodynamic considerations.

You are correct, Bob, for a single particle MODEL. But the reality of the
situation is more complicated. Two internal non-conservative forces are
involved in a process by which internal kinetic energy K (macroscopic)
is converted into thermal energy (microscopic). And if my understanding
of Bruce Sherwood is correct (his AJP article was mentioned here) it is
not at all obvious what fraction of the really-observed x should be used 
to calculate the work correctly.

You are right, it "is a whole new ball of wax!" Any comments on the big
wax creator formed by the meteor? I assume you saw the description. 

                                    Ludwik Kowalski