Re: ENERGY WITH Q

["RAUBER, JOEL" <JOEL_RAUBER@SDSTATE.EDU>]

Ludwik,

I'm a little worried about the Delta Q notation, in the sense of trying to
avoid definitions (and notation, that isn't consistent with later usage.)

The Delta Q notation implies to me, that the calculation only depends on the
endpoints of the process.  Is that what you intend to convey?

Joel R.

ps, this is the old "d q" versus "dbar q" issue.

> -----Original Message-----
> From: Ludwik Kowalski [mailto:kowalskiL@MAIL.MONTCLAIR.EDU]
> Sent: Sunday, October 21, 2001 6:01 PM
> To: PHYS-L@lists.nau.edu
> Subject: Re: ENERGY WITH Q
>
>
> In reading my own messages I see a need for a small correction.
> The amount of heat generated via a dissipative force should be
> labeled as deltaQ while Q should be used as to indicate the
> total amount of thermal energy, for example, 1.5*N*R*T
> (for the ideal monoatomic gas).
>
> In other words mhenergy should have been defined as the sum:
>
> KE+PEgrv+PEspr+deltaQ
>
> and deltaQ should be have been called an increment of thermal
> energy, not the total thermal energy a body contains at a given T.
>
> Another observation is that Model 2 is a good place to
> introduce entropy, S. A change of entropy, deltaS, in an
> elementary thermo-mechanical process, is deltaQ/T. The unit of
> S is J/K. The significance of S can be explained later but the
> positive nature of deltaQ (in Model 2) is a good place to
> indicate that S has a natural tendency of growing.
> Ludwik Kowalski