A car of mass 1500kg arrives at the foot of a straight hill travelling at 30m/s. it reaches the top of the hill 40 seconds later travelling at 10m/s. The length of the hill is 1km and the gain in height is 120metres. The average resistance to the motion is 500N. Find The average power developed by the engine. Answer is 42.5kW. PLEASE HELP UrgenT !