Final answer:
Galileo Galilei disproved the belief that heavier objects fall faster than lighter ones by dropping two objects of different masses from the Tower of Pisa and showing they fall at the same rate in the absence of air resistance.
Step-by-step explanation:
Galileo Galilei made significant discoveries about the acceleration and speed of falling objects. His famous experiment involved dropping two objects of different masses from the Tower of Pisa to prove that, in the absence of air resistance, objects of different masses fall at the same rate due to gravity. This finding was crucial because before Galileo, it was commonly believed that heavier objects fell faster than lighter ones.
During Galileo's experiments, he observed that objects accelerate uniformly; that is, they gain equal increments in speed in equal intervals of time when falling freely or rolling down a ramp. Galileo's investigation led him to formulate the laws of motion in precise mathematical terms, laying the groundwork for other scientists, including Isaac Newton, to further develop the field of classical mechanics.
Answering the specific options provided in the question, the correct statement is 'b) Showed objects of different masses fall at the same rate'. This discovery is pivotal in understanding gravity and the principles of classical mechanics. When Galileo conducted these experiments, he measured the fall time using methods such as his own heartbeat or a water clock, since there were no stopwatches.