Question

A solid metal sphere of $6cm$ diameter is melted and a circular sheet of thickness $1cm$ is prepared. Determine the diameter of the sheet.

Answer 1

Let radius of circular sheet be 'r', then diameter$=2r$, and

Volume of circular sheet=volume of metal sphere

$\Rightarrow \pi r^2\times$ thickness $=\frac{4}{3}\pi R^3\Rightarrow r^2\times 1=\frac{4}{3}\times 3\times 3\times 3\Rightarrow r^2=36\Rightarrow r=\sqrt{36}=6cm$

$\therefore$Diameter $=2r=2\times 6=12cm$