Question

Water is lifted out of a well 30.0m deep by a motor rated at 1.00hp. Assuming 90% efficiency, how many kilograms of water can be lifted in 1 min?
Answer is 137kg but can not figure it out.

Answer 1

mgh/60sec=1hp(.9)(746watts/hp)

mass= 60sec/(9.8N*30m)*747n-m/sec)*.9
=137