* Gravity's Constant Pull: Gravity pulls objects towards the Earth at a constant rate, known as the acceleration due to gravity (approximately 9.8 m/s²). This means that for every second an object falls, its downward velocity increases by 9.8 meters per second.

* Neglecting Air Resistance: In a vacuum (no air resistance), the object's speed would increase linearly.

* Air Resistance: In reality, air resistance plays a significant role. As an object falls faster, it encounters more air resistance, which acts as an opposing force. This force eventually balances out the force of gravity, causing the object to reach a terminal velocity (a constant speed).

In summary:

* Without air resistance: Speed increases at a constant rate due to gravity.

* With air resistance: Speed increases until it reaches a constant terminal velocity.

Key Point: The change in speed depends on the object's mass, shape, and the density of the air.