A coin, a feather, and a brick are dropped from a bridge into a river.
In which order do they hit the water?
How would the order change if the experiment was repeated in a vacuum?
In open air the coin would hit the water first, then the brick would follow and then the feather would hit it last.
The coin is more streamlined than the brick and the feather, so there is less air resistance on the coin.
The feather is light and has a relatively large surface area, and therefore is slowed down more.
Without air resistance, i.e. in a vacuum, all three objects would hit the water at the same time.
They all accelerate at the same rate, and this does not depend on their mass, shape or size.