An iron ball of radius 20 cm is melted and recast into 64 spherical balls of same radius. Find the radius of each spherical ball.
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 5 cm.
Volume of original ball = (4/3) × π × (20)³ = (4/3)π(8000)
Let radius of each small ball = r
Volume of 64 small balls = 64 × (4/3)πr³
Since volume is conserved:
(4/3)π(8000) = 64 × (4/3)πr³
8000 = 64r³
r³ = 125
r = 5 cm