An engine pumps up 100 kg of water through a height of 10m in 5s. Given that the efficiency of the engine is 60%. If `g=10ms^(-2)` the power of the engine is

Options

A. 3.3kW
B. 0.33kW
C. 0.033kW
D. 33kW

Answer

A

Explanation

Work output of engine =mgh
`=100xx10xx10=10^(4)J`
Efficiency `(eta)=("output")/("input")`
`:.` Input energy `=("output.)/(eta)`
`=(10^(4))/60xx100=(10^(50))/6J`
`:.` Power
`=("inputenergy")/("time")=(10^(5)//6)/5=(10^(5))/30=3.3`
`kW`