If there is no air resistance, then both of those balls ... as well as a feather, a piece of paper, a handkerchief, a bowling ball, a fried egg, a hammer, a car, a school bus, an airplane, a diesel locomotive, a computer, and a battleship ... if dropped at the same time from the same height, fall together, and hit the ground at the same time. We've known this for about 400 years, since Galileo.
