Question

Note Use $\mathrm{\pi }=\frac{22}{7}$, unless stated otherwise.
A conical pit of diameter 3.5 m is 12 m deep. What is its capacity in kilolitres?
HINT 1 m³ = 1 kilolitre.

Answer 1

Radius of the conical pit, r = $\frac{3.5}{2}$ m

Depth of the conical pit, h = 12 m

∴ Capacity of the conical pit = $\frac{1}{3}\mathrm{\pi }{r}^{2}h=\frac{1}{3}\times \frac{22}{7}\times {\left(\frac{3.5}{2}\right)}^2\times 12$ = 38.5 m³ = 38.5 kL (1 m³ = 1 kilolitre)

Thus, the capacity of the conical pit is 38.5 kL.