Re: Work-Energy or Work-Kinetic Energy??

[Bob Sciamanda <sciamanda@worldnet.att.net>]

Leigh Palmer wrote:
> > Again, I rest my case regarding the confusion generated by corrupting
> > the pristine definition of work.
>
> OK Bob, I'll bite. What is the "pristine" definition of work and by
> whom was it proclaimed to be so? Which of the meanings of "pristine"
> is intended here?
>
> Leigh

Chill, old man!  I knew "pristine" would draw fire as soon as I typed
it!

Seriously, please don't drag me into a semantic argument, especially
since 
I and the list have chewed this cabbage at length in the very recent
past.
In fact a post of mine laboriously spelled out the conventionaly
accepted 
definition of work and the work-energy theorem.

However . . .
To summarize, by the WE theorem I refer to the usual (dot product)
integration 
of F=ma over the trajectory of the CM of a system of one or more
particles. 
(F= the vector sum of all external forces acting on the particle
system.) 
Nothing more than F=ma and mathematical logic is required to show a
numerical 
equality between this "work integral" and the change in the CM kinetic
energy 
of the particle system.  If energy conservation were abandoned this WE
theorem 
would still be valid.  It is simply a re-statement of F=ma; it applies
to all 
forces, frictional included; it says nothing about universal energy
conservation;  
it knows about no other kinds of energy than kinetic- and this only as a 
convenient numerical quantity as expressed in the theorem. 
It implies nothing about a transfer of energy from the agents of F to
the particle 
system.  The term dw in the first law of thermodynamics is a different
animal, 
both conceptually and numerically except in some carefully contrived
circumstances 
(I suggest that dw in the FLT not be called work, call it adiabatic (or
non-thermal?)
energy transfer.) 

The WE theorem knows nothing about the energy concept implicit in the
FLT.

My contention is that recent tendencies to confound the WE theorem and
the FLT, 
involving different uses of the word "work", are leading to needless
confusion and shedding 
no light;  examples abound on this list (like making the WET a part of
thermodynamics)! 
(all of this has been endlessly discussed quite recently on this
list.)   
-- 


Bob Sciamanda				sciamanda@edinboro.edu
Dept of Physics				sciamanda@worldnet.att.net
Edinboro Univ of PA			http://www.edinboro.edu/~sciamanda/home.html
Edinboro, PA				(814)838-7185

This paper gives wrong solutions to trivial problems. The basic error,
however, is not new.
Mathematical Reviews 12, p561. (Truesdell, Clifford}