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 metal everywhere is $8$ mm thick. Calculate the volume of the metal.

Answer 1

If cylinder has inner diameter is $10.4cm$ and thickness is $8mm=0.8cm$

$\therefore$ outer diameter is $11.2cm$

$\therefore$ volume with outer diameter is $=\pi r^{2}h=3.14\times (11.2{)}^2\times 25$

$=9847.04c{m}^3$

and volume with diameter inner $10.4cm$ is

$=3.14\times (10.4{)}^2\times 25$

$=8490.56c{m}^3$

Now volume of metal is

$=9847.04-8490.56=1356.48c{m}^3$