Question

Identify the free fall situations from the following.

• A. A man landing through a parachute
• B. An apple falling on moon
• C. A rocket propelling into space
• D. A heavy stone falling from a cliff

Answer 1

Answer: (B), (D)

A heavy stone falling from a cliff

During free fall, gravitation is the only force that should act on the body.

• A dense stone falling from a cliff is in free fall under the gravitational force of the Earth. This is valid, because the air resistance is negligible against a dense heavy stone.
• An apple falling on the Moon is under free fall due to the gravitational force of the Moon, and the lack of atmosphere on the Moon to create air resistance.
• A parachute experiences drag force (resistance of air) and thus, another force except gravity acts on it. Hence, it is not under free fall.
• An upward force acts on a rocket during its flight because of the gases it eject. Hence, it is at all free fall.