Question

A rubber shell filled with air forms a rubber ball. The shell’s outer diameter is 12 mm and its inner diameter is 10 mm. Determine the volume of rubber used to make the ball.

A. 523.6 mm³
B. 4.2 mm³
C. 381.2 mm³
D. 46.0 mm³

Answer 1

The radius of outer sphere = half the diameter = 6 mm and of the inner radius = 5 mm.

Volume of rubber = volume of the 'outer' sphere - volume of the 'inner' sphere

Volume of the rubber = 4/3 pi 6^2 - 4/3 pi 5^2 = 46.0 mm^3 Answer