Question

Marbles of diameter 1.4cm are dropped into a beaker containing some water and are fully submerged.The diameter of the beaker is 7cm.Find how many marbles have been dropped in it if water rises by 56cm.

Answer 1

Given
diameter of marble= 1.4cm
radius =1.4/2=0.7cm
volume= 4πr^3
=4*22/7*0.7*0.7*0.7
=4.312cm^3
Now
diameter of a beaker= 7cm
radius = 7/2=3.5cm
height of a beaker
(water level)=56cm
volume= πr^2h
=22/7*3.5*3.5*56
=2156cm^3
number of marbles can be dropped=volume of beaker/volume of marble
=2156/4.312
=500