Re: [Phys-l] energy is well defined

[Jack Uretsky <jlu@hep.anl.gov>]

Hi Bill-
	Whoops! Too many messages.
	My last referred to the question about water.
	So you do have the word "energy" in your vocabulary.  I insist 
that if you use a word you must have, implicitly at least, a definition: 
namely, an explanation of what you mean by the word.  Otherwise you are 
just making comforting (or disturbing) sounds, like a mom to her newborn 
infant.
						Regards,
							Jack





On Wed, 20 Feb 2008, Bill Nettles wrote:

> Hi Jack --
> Now I'm really puzzled :(
> > > > Jack Uretsky <jlu@hep.anl.gov> 2/20/2008 4:51 pm >>>
> > > > Hi Bill-
> > > > Please note that my question did not use the word "energy".
>
> Which question, the mixing of water or the mammal? The mammal question specifically said  "energy." The mixing of water at two different temperatures is explained by energy.
>
> > > Do your students not  do such calculations?
>
> Which calculations, the water or the mammal? Of course,
 we do water at different temps. And I explain that there is a redistribution
of the kinetic energy among the population of molecules. Heat lost = heat
gained  is just a transfer of energy.
> > > > I do not understand your response to answer  my question.  Regards, Jack
>
> So what other way is there to answer it without avoiding energy concepts? You said "How do you describe what happens...." I described it. What else is there?
>
> All the Best,
> Bill
>
> > > > > > Jack Uretsky <jlu@hep.anl.gov> 2/18/2008 11:10 pm >>>
> > >
> > > > Hi Jeff-
> > > > How do you describe what happens when I mix a kilogram of 79
> > > > degree water with a kilogram of 40 degree water in an insulated container?
> > > > Regards,
> > > > Jack
> > >
> > > Jack: The kinetic energy of the molecules in the 79 deg. water is redistributed to more molecules which had less KE on the average. The molecules do work on each other during collisions, gaining or losing KE with the ultimate result being a temperature  between 79 and 40  (59.5 if we ignore the work done to the inside surface of the container) with an average KE per molecule corresponding to that temp. Were you looking for more than that?
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