Here's why:
* Gravity: Gravity pulls the leaf downwards towards the Earth.
* Air Resistance: As the leaf falls, it encounters air molecules. These molecules collide with the leaf, creating a force that acts in the opposite direction of the leaf's motion (upwards). This force is called air resistance or drag.
Factors affecting air resistance:
* Leaf shape and size: A larger, wider leaf will experience more air resistance than a small, narrow leaf.
* Leaf surface area: A leaf with a greater surface area exposed to the air will experience more air resistance.
* Air density: The denser the air, the more air resistance the leaf will encounter.
* Leaf velocity: As the leaf falls faster, it encounters more air resistance.
The result:
Air resistance slows down the leaf's descent. The leaf will eventually reach a terminal velocity, where the force of gravity pulling it down is equal to the force of air resistance pushing it up. At this point, the leaf will fall at a constant speed.
