Re: ENERGY WITH Q

[Robert Cohen <Robert.Cohen@PO-BOX.ESU.EDU>]

Can we say that both friction and tension change the thermal energy of
objects but friction changes it in the block and tension changes it in the
person holding the string?

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Robert Cohen           rcohen@po-box.esu.edu
570-422-3428         http://www.esu.edu/~bbq
Department of Physics
East Stroudsburg University
East Stroudsburg, PA  18301
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> -----Original Message-----
> From: Carl E. Mungan [mailto:mungan@USNA.EDU]
> Sent: Thursday, October 25, 2001 2:06 PM
> To: PHYS-L@lists.nau.edu
> Subject: Re: ENERGY WITH Q
>
> 1. I am not satisfied with merely getting a clear distinction between
> thermal and nonthermal energy unless someone can also give me a clear
> distinction between the mechanisms for *changing* each of these
> (either separately or simultaneously, as long as you tell me how to
> calculate how big the change in each term individually is). I posed
> this question the other day and I have not seen an answer yet. Here
> it is again. I stop a block with a string. No change in the block's
> thermal energy occurs. Now I stop the block via sliding friction. The
> block's thermal energy changes. Why does friction change the thermal
> energy of an object but tension does not (in these particular
> situations)? Give me an algorithm for deciding how a particular force
> changes the thermal energy, in other words, for partitioning the
> changes in the two terms on the RHS of the First Law (which I usually
> call mechanical and internal energy, but would not necessarily be
> adverse to calling nonthermal and thermal energy).