A solid metallic sphere of radius 9 cm is melted and recast into a wire of radius 2 cm. What is the length of the wire?

243 cm

Volume of a sphere = \(\frac{4}{3}\)πr³,

Volume of a wire = πr²l, where 'l' is its length.

Volume of the sphere = \(\frac{4}{3}\)π(9)³=972π cm3 

Volume of the wire = = π(2)²l = 4πl cm³

By equating volume of sphere and volume of wire we get,

972 × π = 4 × π × l 

l = \(\frac{972}{4}\) = 243 cm