Question

A solid toy is in the form of a right circular cylinder with a hemispherical shape at one end and a cone at the other end. Their common diameter is $4.2cm$ and the height of the cylindrical and conical portions are $12cm$ and $7cm$ respectively. Find the volume of the solid toy. (Use $\pi =22/7$)

Answer 1

We have
volume of the solid toy $=$ volume of the conical portion $+$ volume of the cylindrical portion $+$volume of the hemispherical portion

Let $V$ be the volume of toy

$V=\frac{1}{3}\pi r^{2}h+\pi r^{2}h+\frac{2}{3}\pi r^3$

$=\frac{1}{3}\pi \times {\left(2.1\right)}^2\times 7+\pi \times {\left(2.1\right)}^2\times 12+\frac{2}{3}\times \pi \times {\left(2.1\right)}^3$

$=(32.31+166.16+19.38)c{m}^3$

$=217.85c{m}^3$