Question

A hemispherical tank is made up of an iron slieet $1 \mathrm{~cm}$ thick: If the imner radius of the tank is $1 \mathrm{~m}$ then find the volume of iron used in the tank.

Answer 1

 Inner radius of the tank $=1 \mathrm{~m}=100 \mathrm{~cm}$.

Outer radius of the $\tan \mathrm{k}=(100+1) \mathrm{cm}=101 \mathrm{~cm}$.

Volume of iron used in the hemispherical tank

$$

\begin{array}{l}

\left.=\frac{2}{3} \pi \times 1(101)^{3}-(100)^{3}\right) \mathrm{cm}^{3} \\

=\frac{2}{3} \times \frac{22}{7} \times(1030301-1000000) \mathrm{cm}^{3} \\

=\left(\frac{2}{3} \times \frac{22}{7} \times 30301\right) \mathrm{cm}^{3}=\frac{1333244}{21} \mathrm{~cm}^{3} \\

=63487.81 \mathrm{~cm}^{3} .

\end{array}

$$

Hence, the volume of iron used in the tank is $63487,81 \mathrm{~cm}^{3}$.