Answer
See explanation.
Work Step by Step
The force of gravity on a sphere is proportional to the mass of the sphere itself, as seen in the equation for gravity, 13.3. If this is the net force, this equals the mass multiplied by the acceleration.
The mass cancels out on both sides of the equation, as seen in equation 13.4, and the acceleration is the same for any mass.
In other words, a larger mass feels a greater force than a smaller mass, but is also harder to accelerate, and the acceleration ends up being the same.
