1. Sep 7, 2010

### AxiomOfChoice

What's the difference?

2. Sep 7, 2010

### Staff: Mentor

What are definitions?

3. Sep 7, 2010

### AxiomOfChoice

Well, from what I can tell, saying a transformation of a system is isothermal indicates no net change in the internal energy of the system, implying $\Delta U = 0$, implying $W = -\Delta Q$. Adiabatic changes only entail no heat being added or subtracted to or from the system. So there isn't necessarily a zero change in U, since the system can do work, or have work done on it.

Is everything I've said right?

4. Sep 7, 2010

### Dickfore

Last edited by a moderator: May 4, 2017