Question

Eight solid metallic spheres each of diameter 4 cm, are melted to form a single bigger sphere. find the radius of the bigger sphere.

Answer 1

volume of one sphere = 4/3πr^3 = 32/3π cm^3 as diameter is 4 cm radius is 2 cm.
For 8 similar sphere volume of 8 sphere is 8×32/3π cm^3= 256/3π.
if 8 sphere is melted to form a bigger sphere then the volume of all 8 sphere is equal to the bigger sphere.
so,
256/3π=4/3πr^3
r^3=64
r=4cm answer.