1. The problem statement, all variables and given/known data 2. Relevant equations V=IR P=I^2 R 3. The attempt at a solution What does it mean physically and intuitively "power entering the source" ? That might be a start in getting me to understand why the answer is just negative the power dissipated in the resistance. What does negative power entering the source mean physically and where does this negative come from mathematically in the equations?