Question

$\frac{3}{4}th$ part of hemi-spherical tank is filled up of water. It is emptied by a pipe at $14\frac{2}{7}$ litre/ sec. If the diameter of the tank is $4m$ then how long will it take to empty?

Answer 1

Radius of hemisphere$=2m$

Volume of the hemisphere$=V=\frac{2}{3}\times \pi \times r^3=\frac{2}{3}\times \pi \times r^3=16.75516m^3=16755.16l$

Volume of water$=\frac{3}{4}\times V=12566.37l$

14.28l are emptied in 1 second

So the time taken to empty the tank$=\frac{12566.37}{14.28}=879.99\approx 880seconds$

Time required to empty the tanks is $880$ seconds.