1. Sep 29, 2005

### moonman

I have in front of me an equation for energy in a system [ U=U(P,V) ]. I'm being asked to find "the equation of the adiabats in the P-V plane". What are they looking for? I know an adiabat is a system with no heat transfer, meaning that the energy of the system would equal the work done on the system. But what is this equation that they are looking for?

2. Sep 29, 2005

### GCT

well, I'm guessing that if you have U in terms of P, V, solve for P and substitute $$\Delta U =C_v \Delta T$$ for U (first putting it in the form $$\Delta U$$)...the equation of the P,V graph? An equation for P?

3. Sep 29, 2005

### moonman

I don't think that will help with anything. If it's an adiabatic process, deltaT will be zero.

4. Sep 29, 2005

### GCT

no, for an adiabatic process q is zero, the work of an adiabat is equal to the change in its internal energy, the work is equal to constant volume internal energy, the equation I've shown above.

you better get studying

also post the exact problem