Question

A cylindrical tube, open at both ends, is made of metal. The internal diameter of the tube is 10.4 cm and its length is 25 cm. The thickness of the metal is 8 mm everywhere. Calculate the volume of the metal.

Answer 1

Length of metallic tube, h = 25 cm

Inner diameter = 10.4 cm

$\therefore$ Radius (r) = $\frac{10.4}{2}$= 5.2 cm

Thickness of metal = 8 mm

$\therefore$ Outer radius (R) = 5.2 + 0.8 = 6.0 cm

Volume of metal used

= $\pi (R^2-r^2)\times$ h =$\frac{22}{7}(6^2-{5.2}^2)\times 25c{m}^3$

=$\frac{22}{7}(6+5.2)(6-5.2)\times 25c{m}^3$

=$\frac{22}{7}\times 11.2\times 0.8\times 25c{m}^3=704c{m}^3$