To calculate for the power developed in the elevator motor in ft.lb/s, we multiply the distance and the weight of the elevator and divide the product by the time.
Power = (10 ft)(2200 lb) / 20 s = 1100 ft.lb/s
Next, convert the calculated value to HP.
1100 ft.lb/s x (1 HP/ 550 ft.lb/s) = 2 HP