Question

A solid metallic sphere of radius 3 cm is melted and drawn into a cylindrical wire of radius 5 mm. Find the length of the wire.

Answer 1

• 144 cm

Explanation:

Given

• Radius of a sphere = 3 cm
• Radius of a cylinder = 5 mm = 0.5 cm

Volume of a sphere

• V = 4/3πr³= 4/3*3³π = 36π cm³

Volume of a cylinder

• V = πr²h = π*0.5²h = 0.25πh cm³

Comparing volumes to get the length of the wire

• 36π = 0.25πh
• h = 36π/0.25π = 144 cm