Question

Find the mass of a $3.5m$ long lead pipe, if the external diameter of the pipe is $2.4cm$, thickness of the metal is $2mm$ and the mass of $1{cm}^3$ of lead is $11.4$ grams.

Answer 1

Volume of pipe$=\pi (r_2^2-r_1^2)\times h=\frac{22}{7}({\left(\frac{2.4}{2}\right)}^2-{(\frac{2.4}{2}-0.2)}^2)\times (3.50\times 100)$

$=1100(1.44-1)=1100\times 0.44$

$=484c{m}^3$

Weight of pipe$=484\times 11.4=5517.6g=5.518kg$