Re: [Phys-l] PV question

[John Mallinckrodt <ajm@csupomona.edu>]

Brian Whatcott wrote:

> Perhaps if I concede that I defined the process in question too  
> narrowly (after all the ascii diagram shows that pressure doubles  
> while the volume halves, apparently)   then John will not demur if  
> I deny that a pressure changing process is isobaric, nor suppose  a  
> volume changing process is isochoric?   :-)

FWIW, I happily so concede!  Still, referring back to the comment  
that motivated my response in the first place:

> ... a straight line on a P-V diagram would cross isotherms  
> unnecessarily - so cannot be reversible


Cutting isotherms once, twice, or arbitrarily many times is  
irrelevant to the question of whether or not a process is reversible.

John Mallinckrodt
Cal Poly Pomona