The power supplied by a certain source is a constant 7.5 W over the first 5.8 min, zero for the next 2.8 min, a value that increases linearly from zero to 10 W during the next 8.8 min, and a value that decreases linearly from 10 W to zero in the following 5.9 min. Find: the total energy in joules expended during this 23.3 min interval the average power in watts during this time. WTotal = kJ Pavg = W