Re: heat is a form of energy

[Timothy Folkerts <tfolkert@TIGER.FHSU.EDU>]

I was talking about definitons a week a ago, and now it seems to be coming
full circle....


One of the big problems in this debate is, I believe, that people are using
different definitions of heat.  The original question asked -

> would it be correct to say that heat is a form of energy ? if this is
> incorrect, how may this be corrected ?

*** Colloquially, heat is equated with internal energy = thermal energy =
heat energy = U.  In this context, the author is mostly correct.
*** Scientifically, heat is a transfer of energy due to temperature
differences = Q.  In this context, he is mostly incorrect.

To this end, I would vote for  f.  Serway, Physics, 3rd Edition, since he
addresses this question the most clearly.
"There is a major distinction between concepts of heat and the internal
energy
of a substance.  The word heat should be used only when describing energy
transferred from on place to another.  That is, heat flow is energy
transfer
that takes place as a consequence of temperature differences only.  On the
other hand, internal energy is the energy a substance has because of its
temperature."

Furthermore, for just this reason, I would vote for removing "heat" from
the physics vocabulary.  It's colloquial meaning (heat = energy) is too
widespread and too different from it's official scientific meaning (heat =
transfer).

Not that my opinion counts much :-( but I think I would choose
   U = "thermal energy"
   Q = "thermal transfer"
So dU = dQ + dW = "the change in thermal energy of a system is equal to the
thermal transfer into the system plus the work done on the system."


Just my $0.02
Tim Folkerts