Question

$500$ persons are taking a dip into a cuboidal pond which is $80$m long and $50$ m broad. The rise of water level in the pond in millimetres, if the average displacement of the water by a person is $0.04m^3$.

Answer 1

Volume of water displaced by one person $=0.04m^3$

Therefore, volume of water displaced by $500$ persons $=0.04m^3\times 500$$=20m^3$

Area of the tank $=80\times 50m^3=4500m^2$

Now, height to which water rises

$=\frac{totalvolumeofwaterdisplayed}{areaoftank}=\frac{20}{4000}m=0.005m=5mm$