Question

A heap of rice is in the form of cone of diameter 24 m and height 3.5 m. Find the volume of rice. How much canvas cloth is required to cover the heap?

Answer 1

$$\begin{gathered} \mathrm{Hi}, \\ \mathrm{Here}\mathrm{r}=24/2=12\mathrm{m} \\ \mathrm{and}\mathrm{h}=3.5\mathrm{m} \\ \mathrm{so}\mathrm{volume}\mathrm{of}\mathrm{heap}\mathrm{of}\mathrm{rice}={\mathrm{\pi r}}^2\mathrm{h} \\ =\frac{22}{7}\times 144\times 3.5=1584{\mathrm{m}}^3 \\ \mathrm{Canvas}\mathrm{cloth}\mathrm{required}\mathrm{to}\mathrm{cover}\mathrm{the}\mathrm{heap} \\ =\mathrm{\pi rl} \\ \mathrm{where}\mathrm{l}=\sqrt{{\mathrm{r}}^2+{\mathrm{h}}^2}=\sqrt{{12}^2+3.5^2}=12.5\mathrm{m} \\ \mathrm{so}\mathrm{here}, \\ =\frac{22}{7}\times 12\times 12.5=471.42{\mathrm{m}}^2 \end{gathered}$$