I'm really only concerned with the setup so I'm just going to ask it in a general sense, rather than the specific problem. 1. The problem statement, all variables and given/known data Suppose you have a constant voltage and the current is described by i(t). Find the total power delivered between time A and time B. 2. Relevant equations 3. The attempt at a solution I got in a discussion with my classmates, and we couldn't settle which way is correct. So P(t) = V*i(t). Would it be set up as ∫ dP from A to B, or ∫ P(t) dt from A to B? The first is summing small bits of power and will return a unit in Watts. The second sums energy and returns a unit in Joules. So which setup is right, and would the total power delivered end up being power, or energy?