Question

A spherical shell of outer radius $r_2$ and inner radius $r_1$ is made of plastic filled with water. Find the volume available for water.

• A. $\frac{4}{3}\pi (r_2^3-r_1^3)$
• B. $\frac{4}{3}\pi \left(r_2^3\right)$
• C. $\frac{4}{3}\pi \left(r_1^3\right)$
• D. $\frac{4}{3}\pi (r_2^3+r_1^3)$

Answer 1

The correct option is C $\frac{4}{3}\pi \left(r_1^3\right)$

The volume of shell having the plastic is $\frac{4}{3}\pi (r_2^3-r_1^3)$ and the volume inside the shell avialabe for water is $\frac{4}{3}\pi \left(r_1^3\right)$ .