Question

$1.1c{m}^3$ of gold is drawn into a wire of $0.1mm$ in diameter.Find the length of the wire in metre.

Answer 1

Volume of gold $=1.1c{m}^3$

Wire $\Rightarrow$ diameter $=0.1$ mm

Radius$=0.05$ mm $=\frac{0.05}{10}$cm

volume of wire$=\pi r^{2}h=$volume of gold

$\frac{22}{7}\times (0.005{)}^{2}h=1.1$

$h=\frac{1.1\times 7\times (1000{)}^2}{22\times 0.005\times 0.005}=14000$ cm

Length of wire$=14000$cm

$=140$ m$[1$ m$=100$ cm$]$.