Respuesta :
If they're dropped from the same height at the same time and there's no air resistance, the the lighter ball and the heavier ball, as well as a feather, a hammer, a bowling ball, a speck of dust, a school bus, and a battle ship, will all fall side-by-side and hit the ground at the same time.
We've known this for about 400 years, since Galileo. And we've known WHY for about 300 years, since Newton.