Question

A pump is used to lift 500kg of water from a depth of 80m in 10s. Calculate: (i)the power rating of the pump it its efficiency is 40%. (Take g=10ms².)

Answer 1

Let's find work !
Work = Mass × Displacement
Work = 500 × 80
Work = 400000 J
We know,
Power(P) = Energy/Time
Power(P) = 500 × 10 × 80/10
Power(P) = 40000 W or 40 kW
According to question, we need to find power rating.
So, we know
Power rating = Useful power/ Efficiency 
Power rating = $\frac{ \frac{40}{40} }{100}$
Power rating = 100 kW

Answer 2

Answer:

The answer is 100kW...

Explanation:

Formula:

Power = energy / time

Power(P)=500*10*80/10

Power(P)=40000W or or 40kW

Power rating=Useful power/efficiency

power rating=40/40 whole divided by 100

Therefore Power rating = 100 kW...

Hope it helps you...