Physics problem : potential energy

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)?
Hint: 746 Watts equals 1 horsepower

E=mgh=2000*9.8*5.5

E=107800 J

P=E/t=107800/60(secs)

P=1800 Watts

P(horsepower)=P/746

P=2.41 Horsepower

Work done = mgh
work done per second = power
so power = 2000* 9.8 * 5.5 / 60 ( mgh per second)
= 1.8 kw