Re: [Phys-l] teaching energy

["Jeffrey Schnick" <JSchnick@Anselm.Edu>]

 Krishna Chowdary wrote, on Oct. 3, 2006
> How does one address the rest mass energy of an object (I'm happy to
limit to fundamental particles)?

Here's my take on that:

In the reference frame in which the center of mass of the system is at
rest, both the kinetic energy and the potential energy of a system
contribute to the inertia of that system (where the potential energy
contribution may be negative).  The rest masses of the particles in the
system represents yet another contribution to the total inertia of the
system.  Multiplying the total inertia of the system by the square of
the speed of light gives the total energy of the system.  Thus, we have
three broad categories of energy: kinetic energy, potential (a.k.a.
configuration) energy, and rest mass energy.

If the system is going to be interacting with another system, then the
kinetic energy associated with the translational motion of the system as
a whole is also relevant, but that energy can be considered to be the
contribution of the system to the total energy of a supersystem in the
center of mass reference frame of the supersystem.

Jeff Schnick