A falling object on which gravity is the only force is called a free-falling object.

Here's what makes an object free-falling:

* Only Gravity Acts: The only force acting on the object is the force of gravity. This means there's no air resistance, no friction, and no other external forces pushing or pulling on it.

* Constant Acceleration: In a vacuum, all free-falling objects accelerate at the same rate, regardless of their mass. This acceleration is due to gravity and is usually denoted as 'g', approximately 9.8 m/s².

Important Notes:

* Air Resistance: In reality, air resistance is almost always present when an object falls. This force opposes the downward motion and slows the object down.

* Vacuum: To achieve a true free-fall scenario, the object needs to be in a vacuum where there is no air.

Let me know if you have any other questions!