1. The problem statement, all variables and given/known data A resistor with R1 = 25.0Ω is connected to a battery that has negligible internal resistance and electrical energy is dissipated by R1 at a rate of 36.0W. If a second resistor R2 = 15.0Ω is connected in series with R1, what is the total rate at which electrical energy is dissipated by the two resistors? 2. Relevant equations Equivalent resistance (series) = R1 + R2 + ... + Rn Power output = VabI = I2R = (V2)/R 3. The attempt at a solution Since the two resistors are in series, I used the above equation to find Req = 40.0Ω. However, my goal is to find the total rate at which electrical energy is dissipated by both resistors (i.e., the power output), so I need to use one of the expressions for power to obtain my solution. I chose to use I2R to find the power output, so I solved for current to get 1.2A. Since resistors in series have the same current going through them, Req should also have the same current going through it (please correct me if I'm wrong). So, I reused this expression to find the total power output of the combined resistors Req to obtain 57.6W. The problem is that my textbook's solution manual gets a different answer, and they use a different expression to solve for power output (they use (V2)/R). I thought that we can just choose any expression. Can anyone explain why my answer is wrong?