Physics help, have the answer, bu don't know how it was found?

Question

A pump lifts 2000 kg of water per minute up a height of 5.5 m. What horsepower is required (neglecting inefficiency and friction of water in the hose)?

Answer: 1800 W = 0.24 hp (1/4 hp) ( i seem to keep on going in a circle)

Answer 1

Mass x g = weight = force

force (kg) x distance (m) = work (J)

Power (W) = work/time (s); since it's "per minute", time = 60s

Plug in the numbers.

Answer 2

Power is energy/time, so you have

mgh/t = P; P = 2000 kg x 9.8 m/s^2 x 5.5 m/60 s = 1797 W

Since 1 HP = 746 W, P = 2.4 HP

Your answer is off by a factor of 10.

Answer 3

I don't know. Sorry...But....

Please answer mine, it's really important! (to me at least) --> http://answers.yahoo.com/question/index?...