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## Homework Statement

Hi all

I'm a little confused about work in gases. I thought I knew it now I'm not so sure. Basically I'm answering a question about work done

**on**the gas in a reversible cycle where a change in temperature (T1 -T2)at constant volume (V1) is followed by a change in volume at constant temperature (V1-V2), and back again (T2V2-T1V2 then T1V2-T1V1).

I've gone through the maths numerous times and the only way I can think to make my answer match the given one is two have the cycle begin with cooling (T2<T1).

However, there is nothing in the problem set up that indicates it should be in that direction. Therefore starting the cycle with heating (T1>T2) seems equally valid, however the resulting answer is the opposite sign of the given one.

Am I missing some fact that would tell me why it should be cooling. There's no mention of the process being adiabatic as well as reversible so I can't immediately assume Joule cooling.

## Homework Equations

For a reversible process Work done

**on**the gas:

[tex] dW = - P.dV[/tex]

## The Attempt at a Solution

For net work done if (T1<T2) [tex] W = (T_{1}-T_{2})ln(\frac{V_{2}}{V_{1}})[/tex]

Given answer is [tex] W = (T_{2}-T_{1})ln(\frac{V_{2}}{V_{1}})[/tex]

Which implies T2<T2 as I read it.