Final answer:
In the volume formula V(r) = ar for a soccer ball, 'a' is a constant that encapsulates factors like (4/3)π and depends on the ball's shape and material.
Step-by-step explanation:
In the function V(r) = ar, where V represents the volume of air inside a soccer ball and r is the radius of the ball, the constant 'a' signifies a specific factor that accounts for the geometric properties of the sphere. When considering the volume of a sphere, the general formula is V = (4/3)πr³. In this case, 'a' would encapsulate the (4/3)π part of the formula, which remains constant and relates to the shape and material of the ball, making C) A constant that depends on the ball's shape and material the correct answer.