If you dropped a bowling ball and a feather from the top of a tall building, which do you think would hit the ground first? It’s pretty safe to assume that it would be the bowling ball, as you’d think the feather would gently waft down to the ground while the bowling ball would plummet down. And that is exactly what would happen. But even though the objects would hit the ground at different times, in fact, all objects actually fall at the same speed, no matter what their mass is. The different falling speeds we witness as the objects drop is all to do with air resistance.
Floating on air
A falling feather is so light that the air offers much greater resistance to it than it does to the bowling ball. The air is an upward force of friction, which counteracts gravity and slows down the speed at which the feather falls.
Under pressure
One way of experiencing air resistance yourself is to put your open hand out of the window of a moving car. Ask your parents’ permission first though, and make sure to check there are no other cars around! When your hand is out, you’ll be able to feel the air pressing against your hand. If the car speeds up, the air resistance force will get stronger. If you clench your hand into a tight fist, you’ll feel that the force decreases due to less friction.
Vacuum up
We know that air resistance is the reason for the feather falling slowly because scientists have conducted the bowling ball and feather experiment by dropping the bowling ball and feather in more than one place. This includes a glass chamber that has had the air pumped out. This airless chamber creates a vacuum, and inside it the feather and bowling ball hit the ground at exactly the same after falling at exactly the same speed.
Mooning around
This amazing fact was even tested on the moon. In 1971, Apollo 15 Commander David Scott dropped a hammer and a feather (which was 44 times lighter than the hammer!) and they both hit the ground simultaneously!
