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Re: ENERGY WITH Q

In the context of:

And it then follows that energy increase of the system = the decrease of
the energy of the applicator. Total KE is conserved -- always -- even
for a complicated interaction with multiple particles.

At 12:40 PM 11/27/01 -0500, Bob Sciamanda wrote:
Not so! even if F1=-F2, there are many cases where ds1 is not equal to
ds2...

As usual, Bob is exactly right.

Subparts of the energy are not separately conserved:
-- potential energy is not separately conserved.
-- kinetic energy is not separately conserved.
-- thermal energy is not separately conserved.
-- nonthermal energy is not separately conserved.

Total energy is conserved!
-- The sum of (KE + PE) is conserved.
-- The sum of (thermal energy + nonthermal energy) is conserved.

=================================================================

Related subject: Terminology:

I've been doing a survey, talking to physicists. Not physics
teachers, but people who do physics research for a living.
-- I ask them for the technical definition of "work".
100% of them answer "Force dot distance".
-- I ask them for the corresponding definition of "pseudowork".
100% of them give me funny looks.
0% have ever heard of the term before.
(Nearly 100% of them fall back to a non-technical
definition: pseudowork is what management does :-)