Find the volume of a sphere whose radius is 0.63 m.

Find the amount of water displaced by a solid spherical ball of diameter 28 cm.

The diameter of a metallic ball is 4.2 cm. What is the mass of the ball, if the density of the metal is 8.9 g per cm³?

The diameter of the moon is approximately one-fourth of the diameter of the earth. What fraction of the volume of the earth is the volume of the moon?