Question

A well 20m deep of diameter 4m is full of water. Find the work done inlifting all the water from the well ​

Answer 1

Answer:

Work done in lifting all the water from the well is 4.92 MJ

Explanation:

Volume of the water in well is

$V=\pi r^2h\\V=\pi \times 2^2\times 20\\V=80\pi m^3$

We know specific gravity of water is s= 1000

Quantity of the water

$m =S\times V\\m=1000 \times 80\pi \\m=80000\pi kg$

Work done  =force x displacement

$W=F\times d\\\W=mg\times d\\W=80000\pi \times 9.8 \times 20\\W=4.92 MJ$

Work done in lifting all the water from the well is 4.92 MJ