# Thermodynamics: internal energy

1. Oct 14, 2013

### iScience

internal energy U=q+W

so far we've only been substituting -PV into W but i just wanted to be sure that the W is the total work and not just the work done by the pressure right?

2. Oct 14, 2013

### Staff: Mentor

Right. Another common kind of work is electrical, when looking at the thermodynamics of batteries and fuel cells, for instance. You will often see fomulations of the kind
$$W = -P dV + W_\text{other}$$