A Level Physics Practice Exam

The acceleration of an object acted on only by gravity is known as the acceleration of free fall. When an object is in free fall, it experiences a uniform acceleration towards the center of the Earth (or any other massive body) due to gravity, which is approximately 9.81 m/s² near the Earth's surface. This acceleration remains constant as long as we neglect air resistance and other forces.

In the context of this question, the other options do not accurately describe the scenario of an object subject only to gravitational force. Zero acceleration would imply that the object is at rest, which contradicts the fact that it's in free fall. Constant acceleration could refer to various scenarios, but alone does not specify the acceleration due to gravity. Acceleration due to friction would not apply here, as friction is not a factor when considering only the force of gravity acting on the object. Thus, the correct answer reflects the specific nature of gravitational acceleration experienced during free fall.