Re: ENERGY WITH Q

[Jim Green <JMGreen@SISNA.COM>]

> Heat and work are energy fluxes at the Control Volume boundary.   We
> are writing a rate equation.

I can not comment on the above except to say I guess the I have no idea of
what is meant.

> ..................... It seems obvious to me that heat and
> work are quite distinct. The distinction is not only useful; it is
> necessary -- if we intend to bring our program of writing rate equations
> for entropy and energy to a successful conclusion.

Of course there is a distinction between Q and W!!  Q changes the entropy
and W does not.  I have never said that they are not distinctive;  I have
only said that the mechanism of doing Q and doing W are basically the
same.  They are booth a form of work done ON the system.

> I cannot think of
> any circumstance where an engineer became confused or even slightly
> troubled in writing out these important rate equations --- always for a
> *particular* problem that he "must solve" [Einstein].   Granted,
> physicists are smarter than engineers.  One should always employ the
> physicist when one of each is available --- unless the solution of
> *your* particular problem has to be correct and cleverosity is not
> important :-)

I can not carefully/politely say just how or why an "engineer" might become
"confused".   When I have been seduced into teaching an engineering class
it has always seemed to me that the class member were always confused.  If
one gets outside of their mysterious problem solving rituals and asks them
to think the situation through, it is they who become mystified.

Further, in my experience a physicist might be hired instead of an engineer
because he is usually paid less - which is another mystery of a different sort.

Jim Green
mailto:JMGreen@sisna.com
http://users.sisna.com/jmgreen