Question

A hollow sphere in which a circus motorcyclist performs his stunts has an inner diameter of $7m$. Find the area available to the motorcyclist for riding.

Answer 1

Given : Diameter of hollow sphere $=7m$

The inner radius of the hollow sphere$=\frac{7}{2}=3.5m$ [Radius $=\frac{1}{2}\times$Diameter ]

Available area to the motorcyclist for riding $=$ Inner surface area of the sphere

$=4{\mathrm{\pi r}}^2$

$$\begin{gathered} =4\times \frac{22}{7}\times 3.5\times 3.5 \\ =154m^2 \end{gathered}$$

Hence, the area available to the motorcyclist for riding is $154m^2$.