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?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e 243 cm.
Let's assume the length of the wire is 'y' cm.
A solid metallic sphere of radius 9 cm is melted and recast into a wire of radius 2 cm.
The volume of the sphere = Volume of the wire.
4/3 × π ×(radius of sphere)3 = X (radius of wire)2 x y
4/3 × π × (9)³ = π × (2)² × y
4/3 × 93 = 4y
1/3 × 729 = y
length of the wire = y = 243 cm.