Here's why:
* Gravity: The primary force acting on a freely falling body is gravity. This force pulls the object towards the center of the Earth.
* Constant Force: The gravitational force acting on an object near the Earth's surface is essentially constant. This means the force pulling the object downwards doesn't change significantly as it falls.
* Constant Acceleration: Since force causes acceleration (Newton's Second Law: F = ma), and the gravitational force is constant, the acceleration of the falling object is also constant.
Important Considerations:
* Air Resistance: In reality, air resistance plays a role. As an object falls faster, the air resistance (drag) increases, opposing the gravitational force. This slows the acceleration down until the object reaches a terminal velocity, where the force of air resistance equals the force of gravity, and the acceleration becomes zero.
* Distance from Earth: The further away an object is from the Earth's surface, the weaker the gravitational force becomes. This means the acceleration due to gravity decreases with altitude. However, for objects falling close to the Earth's surface, this variation in gravitational force is negligible.
In summary:
While the acceleration of a freely falling body is ideally constant and equal to 'g', factors like air resistance and distance from Earth can affect the actual acceleration observed.
