What is the power of a pump which takes 10 seconds to lift 100 kg of water to a water tank situated at a height of 20 m? (`g = 10 m s^(-2)`)

Options

A. 15 kW
B. 2 kW
C. 25 kW
D. None of the above

Answer

B

Explanation

`W = m xx g xx h`
Here, Mass of water, m = 100 kg
Acceleration due to gravity, `g = 10 m s^(-2)`
And, Height, h = 20 m
So, putting these values in the above formula, we get :
Work done, `W = 100 xx 10 xx 20`
= 20000 J
And, Time taken, t = 10 s
Now, we know that:
`"Power", P = (W)/(t)`
`= (20000)/(10)`
= 2000 watts (or 2000 W)
Thus, the power of this pump is 2000 watts. This power can be converted from watts into kilowatts by dividing it by 1000.
So, `"Power" = (2000)/(1000) "kilowatts"`
= 2 kilowatts `" "` (or 2 kW)