The Principle of Equivalence

The key principle behind this is the Principle of Equivalence, a cornerstone of Einstein's theory of General Relativity. This principle states that:

* Gravitational and inertial mass are equivalent. This means that the mass that determines how much an object is pulled by gravity (gravitational mass) is the same as the mass that resists changes in motion (inertial mass).

How It Applies to Falling Objects

* Gravity acts equally on all objects: The force of gravity depends only on the mass of the object and the mass of the Earth. It doesn't depend on the size or shape of the object.

* Acceleration due to gravity is constant: Since the force of gravity is the same on all objects near the Earth's surface, the acceleration they experience due to gravity is also the same. This acceleration is approximately 9.8 m/s².

The Role of Air Resistance

Air resistance is a force that acts in the opposite direction of motion. It's why a feather falls slower than a rock. If there were no air resistance, a feather and a rock would fall at the same rate.

In Conclusion

In the absence of air resistance, all objects near the Earth's surface fall with the same acceleration due to gravity because the gravitational force acts equally on them, regardless of their size or weight.