Question

Water is pumped steadily out of a flooded basement at a speed of 5.0 m/s through a uniform hose of radius 1.0 cm. The hose passes out through a window 3.0 m above the waterline. What is the power of the pump?

Answer 1

Power = force x velocity

volume/sec = cross sectional area x 5m/sec

cross section area of hose = 3.14286 square centimeters = .000314286 square meters

volume = 0.0015714 cubic meters /sec = 1.5714 kg / sec

1.5714 kg raised 3.0 m every second.

Power = f x v

Power = 1.5714 x 9.81 x 3.0 = 46.247 watts