1. The problem statement, all variables and given/known data A disc of conductivity σ is in an axial magnetic field B = B0cosωt The disc has radius a and thickness s 2. Relevant equations possibly dP/dv = JE (dot product of two vectors) but I have absolutely no clue if it is relevant or not. I think J=σE might be relevant, but I have no idea. 3. The attempt at a solution I really don't know where to begin with this. I know that P= I V but I am completely lost as to whether or not I am supposed to derive the potential difference from the magnetic field, or what. This should be a simple plug- and - chug problem, but I can't seem to figure out where to begin, and I am feeling stupid because this is the first one in the problem set. Am I supposed to derive the electric field from the B field?