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 into a solid cylinder of diameter 14 cm, find the height of the cylinder.

Answer 1

Internal radius of the hollow spherical shell = \(\frac{6}2\) = 3 cm 

And external radius of that shell = \(\frac{10}2\) = 5 cm 

Radius of the cylinder = \(\frac{14}2\) = 7 

Let height of the cylinder be x cm 

According to the question, 

Volume of the cylinder = volume of the spherical shell

∴ height of cylinder = \(\frac{8}3\) cm