Picture retrieved from https://www.youtube.com/watch?v=p_o4aY7xkXg
We all know that gravity always pulls everything towards the center of the earth, that is why when we jump, we fall right back down to the ground instead of floating in the air. Furthermore, we've also learned that when an object is in free fall, which means the only force acting on it is gravitational force, it does not matter at all how much the object is weight.
F = ma
Since the only force acting on the object is gravitational force,
mg = ma
g = a
Since the only force acting on the object is gravitational force,
mg = ma
g = a
Since the mass cancels out, it has no effect at all on the fall. This is why a rock and a feather would fall down at the exact same speed when there is no air resistance. Because of how advanced technology is nowadays, NASA was able to create the world's biggest vacuum chamber to prove this theory.
Although what happens in this video is really cool, we know that this is not what happens in real life. The important force that comes into play is drag force, which is discussed on the next page.