Re: COLLISION 2

[brian whatcott <inet@INTELLISYS.NET>]

At 19:16 11/29/99 -0700, Jim  wrote:
///
> Any action which gets the water hotter, I would call "heating".  But not
> necessarily connected with a DQ.

There is a conflict here. You have mentioned that putting a cup of water
in a microwave in some strict sense is not heating.
(Or perhaps it was someone else.)

///
> In the case of radiative heating I am lost, except to say that "something"
> must do work on the water/system.  I would only very cautiously talk about
> "photons" in the case.
>
> Remember that ALL heating (dE>0) is by doing WORK.  What remains is the
> partitioning of that "work" into DQ and DW -- in cases where it
> matters.  In the case of the piston/cylinder this is easy.  For other
> processes this is NOT so easy.///


> Jim Green

This seems to be the root of the concept:
that heating 'works' by doing work.

This is certainly not a casually arrived at position.
But I cannot place it. It is not (I think) a model that
is often shared by engineers.

    These fellows see a 1 HP motor turning a bandsaw.
 They see the work embodied in aluminum chips falling from the
sawn plate. They know - or think they know - that besides  740
watts of work, there is 740 watts of heating expended on the air
round the motor, on the warm (sometimes painfully hot) chips
and on the hot plate that remains to be sawn.
That motor paid back in work and heat 200%!

They contrast this with an electric element heater - it might
 be rated at 750 watts - but all it can do is provide 750 watts
of warmed environment - no chips or other signs of progress!
 All it could give was 100%

I am sure that this is much less than a respectable view.
 What would you say?





brian whatcott <inet@intellisys.net>
Altus OK