Question

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

Answer 1

Length of metal tube(h) = 25cm
Interanl diameter=10.4cm
$\therefore$ Internal radius(r) = $\frac{10.4}{2}=5.2cm$
Thickness of metal = 8mm =0.8cm
$\therefore$ Outer radius =5.2 +0.8 =6cm
Now volume of the metal
$=\pi h(R^2-r^2)=\frac{22}{7}\times 25(6^2-{5.2}^2)c{m}^3=\frac{550}{7}(36-27.04)=\frac{550}{7}\times 8.96c{m}^3=\frac{550}{7}\times \frac{896}{100}=704c{m}^3$