Question:
If the radii of the circular ends of a conical bucket which is 45 cm high be 28 cm and 7 cm, find the capacity of the bucket. (Use π = 22/7).
Solution:
The height of the conical bucket is h = 45 cm. The radii of the bottom and top circles are r1 = 28cm and r2 =7cm respectively.
The volume/capacity of the conical bucket is
$V=\frac{1}{3} \pi\left(r_{1}^{2}+r_{1} r_{2}+r_{2}^{2}\right) \times h$
$=\frac{1}{3} \pi\left(28^{2}+28 \times 7+7^{2}\right) \times 45$
$=\frac{1}{3} \times \frac{22}{7} \times 1029 \times 45$
$=22 \times 147 \times 15$
$=48510 \mathrm{~cm}^{3}$
Hence $\quad$ volume $=48510 \mathrm{~cm}^{3}$