What did Galileo's experiment on the Leaning Tower of Pisa demonstrate about falling objects?

Galileo's experiment at the Leaning Tower of Pisa was pivotal in demonstrating that different objects, regardless of their mass, fall at the same rate in the absence of air resistance. By dropping two balls of different weights, Galileo showed that they hit the ground simultaneously. This challenged the long-held Aristotelian belief that heavier objects fall faster than lighter ones.

The principle behind this observation lies in the acceleration due to gravity, which acts equally on all objects in free fall. When air resistance is negligible, the force of gravity accelerates all objects at approximately 9.81 meters per second squared, resulting in a uniform rate of fall irrespective of their mass. This fundamentally altered the understanding of motion and laid the groundwork for classical mechanics.

The other options misunderstand the nature of gravitational acceleration or introduce irrelevant factors, but the core of Galileo's finding was that mass does not affect the rate of fall when only gravitational forces are considered.