For a tenpin bowling ball, the radius is 4.25 inches (10.8 centimeters).
Depends what size the ball is.
The radius is 20mm (2cm).
The size of a regulation volleyball depends on if it is used for indoor or beach volleyball. An indoor ball has the radius of about 21 centimeters, and a beach ball has a radius of about 21.7 centimeter.
The diameter of a pool ball is 2 and 1/4 inch diameter. The radius of a pool ball is 1 and 1/8 inches. The radius is one half of the diameter.
About 1.5 in
Volume of the beach ball: 4/3*pi*radius^3
In the US, a billiards ball or pool ball is 2.25 inches in diameter. This is 1.125 for its radius. The only exception is the oversize cue ball, which is 2.375 inches in diameter.