Adiabat Process - with pV cycle

[hevans1303]

Homework Statement

A heat engine uses 2 mole of a diatomic gas that follows the pV cycle shown, how much work is done, over the cycle if P=100kPa, T₁=207K

* P is suppose to be 0.5P this was a typo on the graph


This is what I've figured out so far: (if i am incorrect on anything please let me know)

W1→2 = 0

W2→3=nRΔT
So it would look like:
(2)(5/2)(8.31)(?-207)
The problem is i can't figure out how to find the other tempurature

W3→1=nRTln(v₂/v₁)
So it would look like this
(2)(8.31)(207)ln(?/?)
I don't understand how to get the volumes in this problem all the other problems i have had have given me a volume.

 

[dikmikkel]

The relevant equations when the work is not equal to zero is the adiabat equations:
From the littarry classic: Thermal Physics , Kittel and Kroemer:
http://books.google.dk/books?id=51_...TgK#v=onepage&q="adiabatic equations"&f=false