1. The problem statement, all variables and given/known data At what rate is a 50 kg boy using energy when he runs up a flight of stairs 10 m high, in 7 s? Provide answer in watts. (Hint: Rate of change of energy is power) Use g=10 m/s2. 2. Relevant equations F=ma W=Fd P=W/T 3. The attempt at a solution 10/7 = .143 = A F = MA, so F = .143*50 = 7.15 W = FD, so W = 7.15 *10 P = W/T, so P = 71.5/7 Is that right? Am I using the correct acceleration and distance and time, or is there more complicated math involved than I thought?