Question

A wooden cylindrical pole is $7m$ high and its base radius is $10cm.$ Find its weight if the wood weighs $225kg$ per cubic metre.

Answer 1

Radius of the base of pole $\left(r\right)=10cm=\frac{10}{100}m=\frac{1}{10}m$ [$\because 1m=100cm$]

and height $\left(h\right)=7m.$

$\therefore$ Volume of cylindrical wooden pole $=\pi r^{2}h$

$=\frac{22}{7}\times \frac{1}{10}\times \frac{1}{10}\times 7m^3$

$=\frac{22}{100}{m}^3$

Weight of $1$ cubic metre $=225kg$

$\therefore$ Total weight of the wooden pole $=\frac{22}{100}\times 225=\frac{4950}{100}$

$=49.5kg$