Question

$2c{m}^3$ of gold is drown into wire $0.1mm$ in diameter. Find the length of the wire.

Answer 1

$2c{m}^3=2\ast {10}^{3}m{m}^3=2000m{m}^3$

Let the length of the wire be l

$2000=l\ast 0.1\ast 0.1\ast \frac{\pi }{4}\Rightarrow l=254777mm$