Question

Lead spheres of diameter 6 cm are dropped into a cylindrical beaker containing some water and are fully submerged. If the diameter of the beaker is 18 cm and water rises by 40 cm. find the number of lead spheres dropped in the water.

Answer 1

$\mathrm{Radius}\mathrm{of}\mathrm{sphere}=\frac{6}{2}=3\mathrm{cm}$

Let n be the no. of spheres are fully submerged.

and height of water raised = 40 cm

Clear,

The volume of raised water = n × volume of a sphere

Hence, no. of lead sphere = 90