Question

A copper sphere of diameter $18$ cm is drawn into a wire of diameter $4$ mm. Find the length of the wire.

Answer 1

Vol. of cu sphere $=$ Vol. of cu wire.

$\Rightarrow \frac{4}{3}\pi r^3=\pi r^{1^2}l$

$\Rightarrow \frac{4}{3}\pi \times 9^3=\pi 2^{2}l\times ({10}^{-1}{)}^2\Rightarrow l=243m$