Question

The diameters of the internal and external surfaces of a hollow spherical shell are 6 cm and 10 cm respectively. If it is melted and recast and recast into a solid cylinder of diameter 14cm, find the height of the cylinder.

Answer 1

Internal diameter of hollow spherical shell = 6cm

Internal radius of hollow spherical shell = 6/2 = 3 cm

External diameter of hollow spherical shell = 10 cm 

External radius of hollow spherical shell =10/2 = 5cm

Diameter of cylinder = 14 cm 

Radius of cylinder = 14/2 = 7 cm

Let height of cylinder = x cm

According to the question

Volume of cylinder = Volume of spherical shell

Height off cylinder = 8/3 cm