Question
A engine pumps up 100 kg of water through a height of 10 m in 5s. Given that, the efficiency of engine is 60%. If g = 10 ms-2, the power of this engine is
3.3 kW
0.33 kW
0.033 kW
33 kW
Solution
A.
3.3 kW
Efficiency of engine η = 60%
Power is equal to the work divided by time.
Efficiency tells how efficient something is and gives a number between 0 and 1.
Power =
=
Given:- m2 = 100 kg
h = 10 m
t = 5s
and g = 10 ms-2
∴ Power =
= 3.3 × 103 W
Power P = 3.3 kW
