A heavy rock and a light rock in free-fall have the same acceleration. The reason the heavy rock doesn't have a greater acceleration is that the
A)force due to gravity is the same on each.
B)air resistance is always zero in free fall.
C)inertia of both rocks is the same.
D)ratio of force to mass is the same.
E)none of the above

Question

Quizplus · Accepted Answer

The acceleration of an object in free fall is determined by the ratio of the gravitational force acting on it to its mass. According to Newton's second law, acceleration is directly proportional to force and inversely proportional to mass (a = F/m). Since the gravitational force on an object is proportional to its mass (F = mg), the mass cancels out when calculating acceleration, resulting in the same acceleration for both heavy and light rocks.

A Heavy Rock and a Light Rock in Free-Fall Have