Question

The diameter of a sphere is 6 cm. It is melted and drawn into a wire of diameter 0.2 cm. Find the length of the wire.

Answer 1

Given that,
Diameter of sphere = 6cm

Radius of sphere =`d/2=6/2cm=3cm=r_1`

Diameter of the wire = 0.2cm 
Radius of the wire =0.1cm = `r_2`

Volume of sphere = Volume of wire

⇒`4/3πr_1^3=πr_2^2h`

⇒`4/3xx3xx3xx3=0.1xx0.1xxh`

⇒`(4xx3xx3)/(0.1xx0.1)=h`

⇒h=3600

⇒ h =36m.

∴ Length of wire=36m.