Re: [Phys-l] Temperture profile in a graviational field

["Folkerts, Timothy J" <FolkertsT@bartonccc.edu>]

I have had several insights -- but let me first address a few of John's
questions.

* The walls of the tube are meant to me perfectly insulating, so no heat
can go in or out through the sides of the tube.  The walls are also
assumed to have a negligible heat capacity and to be perfectly rigid.
This sounds like both isentropic and thermally insulated to me.
* the two pistons, being 1 km apart, are meant to be thermally isolated
from each other.
* Initially, assume the pistons on the ends are also perfectly insulated
and have negligible heat capacity.  
* Later, we can change this to make on or both of the ends a thermal
reservoir with a constant temperature.
* initial conditions for the gas are assumed to be isothermal.  The
initial pressure distribution would depend on the acceleration of the
spaceship (or the acceleration of gravity).
* the time scale I am most interested in is the long-term results for
the co-moving pistons (or for the equivalent cylinder ins a psace ship
or cylinder in the earth's gravity. (But he other cases are also fun to
consider.)



-----Original Message-----
From: phys-l-bounces@carnot.physics.buffalo.edu
[mailto:phys-l-bounces@carnot.physics.buffalo.edu] On Behalf Of John
Denker
Sent: Thursday, January 26, 2012 12:30 PM
To: Forum for Physics Educators
Subject: Re: [Phys-l] Temperture profile in a graviational field

On 01/26/2012 10:38 AM, Folkerts, Timothy J wrote:

> Consider an infinitely long insulated cylinder.  There are two 
> insulated pistons placed far apart with some gas in between (say 1 km 
> apart, with 1 atm of N2 @ 300 K). This makes any processes adiabatic 
> within the tube adiabatic.

.....