Question

A fire engine must lift 30 kg of water a vertical distance of 20 m each second. What is the amount of power needed for the water pump for this fire hose?
P=W/t=Fd/t=mgd/t (30)(9.8)(20)/1= 5880 W is that right?

Answer 1

Power is the rate of doing work. It is the amount of energy consumed per unit time. Having no direction, it is a scalar quantity. We express it as follows:

P = W / t
          where W = Fd
                     F = mg

Therefore,

P = mgd / t
P = (30)(9.81)(20) / 1 = 5886 W