Question

The outer diameter of a spherical shell is 10 cm and the inner diameter is 9 cm.Find the volume of the metal contained in the shell. Also find its outer surface area.

Answer 1

Outer radium $=\frac{10}{2}m=5m$

Inner radium $=\frac{9}{2}m=4.5m$

$\therefore$ Volume of the midule contained in the sheel.

$=\frac{4}{3}\pi R^3-\frac{4}{3}\pi r^3$

$=\frac{4}{3}\pi (5{)}^3-\frac{4}{3}\pi (4.5{)}^3$

$=\frac{4}{3}\pi (125-91.125)$

$=\frac{4}{3}\times \frac{22}{7}\times 33.875=159.69m^3$