Re: Thermal Energy

[John Mallinckrodt <ajmallinckro@CSUPOMONA.EDU>]

On Wed, 6 Mar 2002, Michael Edmiston wrote:

> If we had a nice way to describe/calculate the "organized rotational motion"
> then we could say the thermal energy is... (KE relative to cm) minus (KE
> associated with organized rotation).

Here's what I always use:

   KE associated with organized rotation = (L_cm)^2/(2*I_cm)

where L is the angular momentum of the system calculated about its
center of mass and I_cm is the moment of inertia about an axis
parallel to the angular momentum through the center of mass.

This quantity can *change* without external interactions; it can
even monotonically approach zero, but it cannot be thermalized.

John Mallinckrodt      mailto:ajm@csupomona.edu
Cal Poly Pomona          http://www.csupomona.edu/~ajm