A hollow sphere is what is left of a sphere with radius \(r_{\scriptsize{2}}\), when a sphere with radius \(r_{\scriptsize{1}}\) has been removed from it, the two spheres having the same centre and \(r_{\scriptsize{1}}\)

**< \(r_{\scriptsize{2}}\).**### Formulas

The volume *V* of a hollow ball is:

\(V = \dfrac{4\pi (r_{\scriptsize{2}}^3~ – ~r_{\scriptsize{1}}^3)}{3}\)