Thermal Energy

[Bob Sciamanda <trebor@VELOCITY.NET>]

On Tue, 5 Mar 2002, Bernard Cleyet wrote:

> > Why make rot. KE a form of internal energy?
John Mallinckrodt replied:
> Because it is an invariant property of the body and not (unlike
> translational kinetic energy) of the inertial reference frame
> from which it is measured.

Very true.  Even more obvious, but  noteworthy, of this rotational kinetic
energy is that, until it has been thermalized it can, in principle, still be
converted to work with 100% efficiency.  Once it has been thermalized the
second law of thermodynamics forbids this.  We store energy in rotating
flywheels, rather than in other internal energy mechanisms, so that we can
avoid the 2nd law restriction in recovering that energy.

Bob Sciamanda (W3NLV)
Physics, Edinboro Univ of PA (em)
trebor@velocity.net
http://www.velocity.net/~trebor