A solid hemisphere is melted and reshaped into a sphere of the same radius. How does the volume change?
Show answer & explanation
Correct answer: B
Explanation
Let the radius be r.
Volume of the hemisphere = (2/3)πr³
Volume of the sphere = (4/3)πr³
Sphere : Hemisphere = (4/3)πr³ : (2/3)πr³
= 4 : 2
= 2 : 1
In other words, the volume does not simply double after melting; rather, a sphere made of the same material has twice the volume of the hemisphere.