Here's why:

* Acceleration due to gravity (g) is constant: The acceleration due to gravity near the Earth's surface is approximately 9.8 m/s². This means that every object, regardless of its mass or size, will accelerate downwards at this rate in a vacuum (no air resistance).

* Newton's Law of Universal Gravitation: This law states that the force of gravity between two objects depends on their masses and the distance between them. However, the acceleration due to gravity is independent of the object's mass.

Important Note: Air resistance is a significant factor in real-world scenarios. It opposes the motion of objects, causing lighter objects to accelerate slower and heavier objects to fall faster. This is why a feather and a bowling ball fall at different rates in the air.