Question

A student lift water from well 25m deep. If the work done by the student is 500J, then find the volume of

water? (Take g = 10 m/s2

, Density of water = 1000 kg/m3)​

Answer 1

Given:

A student lift water from well 25m deep. If the work done by the student is 500J.

To find:

Volume of water ?

Calculation:

We are assuming the gravitational acceleration to be constant at all depths and equal to 10 m/s².

Now, let mass of water be 'm':

So, the work done will be equal to potential energy attained by water.

$\therefore \: work =PE$

$\implies \: work = m \times g \times h$

$\implies \: 500 = m \times 10 \times 25$

$\implies \: 500 = m \times 250$

$\implies \: m = 2 \: kg$

Let volume of water be V:

$\therefore \: V = \dfrac{mass}{ \rho}$

$\implies \: V = \dfrac{2}{1000}$

$\implies \: V = 2 \times {10}^{ - 3} \: {m}^{3}$

$\implies \: V = 2 \times {10}^{ - 3} \times 1000 \: litre$

$\implies \: V = 2 \: litre$

So, volume of water is 2 litres.