Question

A cubic cm of gold is drawn into a wire 0.1 mm in diameter, find the length of the wire.

Answer 1

Let x be the length of wire.

Clearly, the volume of gold = volume of wire.

{Volume of gold = 1 cm³ = 1000 mm}

`1000 = pi ((0.1)/2)^2 xx x`

`22/7 xx 1/400 xx x = 1000`

`x = (1000 xx 400 xx 7)/22`

`= (1400 xx 1000)/11`

`= 127300  mm`

` x = 127.3m`

Hence, the length of wire is 127.3 m.