Question

Question 6
A solid iron pole consists of a cylinder of height 220 cm and base diameter 24 cm, which is surmounted by another cylinder of height 60 cm and radius 8 cm. Find the mass of the pole, given that 1 $c{m}^3$ of iron has approximately 8 g mass.

Answer 1

Radius of bigger cylinder = 12 cm, height of bigger cylinder = 220 cm
Radius of smaller cylinder = 8 cm, height of smaller cylinder = 60 cm
Volume of bigger cylinder
$=\pi r^{2}h$
$=\pi \times {12}^2\times 220$
$=31680\pi c{m}^3$
Volume of smaller cylinder
$=\pi r^{2}h$
$=\pi \times 8^2\times 60$
$=3840\pi c{m}^3$
Total volume
$=31680\pi +3840\pi$
$=35520\pi c{m}^3$
$\text{Mass=Density}\times \text{Volume}$
$=8\times 35520\pi$
$=892262.4gm$ (1000gm =1kg)
$=892.3kg$