# Thermodynamics: internal energy

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?

DrClaude
Mentor
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?

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
$$W = -P dV + W_\text{other}$$