Question

A solid has hemispherical base with diameter $8.5cm$ and it is surmounted by a cylinder height $8cm$ and diameter of cylinder is $2cm$. Find the volume of this solid. ($\pi =3.14$).

Answer 1

Radius of hemisphere $\left(r_1\right)=\frac{\text{Diameter}}{2}=\frac{8.5}{2}=4.25cm$

Volume of hemisphere $=\frac{2}{3}\pi {r_1}^3=\frac{2}{3}\times 3.14\times {\left(4.25\right)}^3=160.7{cm}^3$

Also,

Height of cylinder $=8cm$

Radius of base of cylinder $\left(r_2\right)=\frac{\text{Diameter}}{2}=\frac{2}{2}=1cm$

Volume of cylinder $=\pi {r_2}^{2}h=3.14\times 1^2\times 8=25.12{cm}^3$

Therefore,

Volume of solid $=$ Volume of cylinder $+$ Volume of hemisphere

$\Rightarrow$ Volume of solid $=160.7+25.12=185.82{cm}^3$