Explain the Air Resistance

If you drop a feather and a cannonball at the same time from the same height, which will hit the ground first? The cannonball of course. Why does the feather take longer? For its mass it has much more surface area bouncing against air molecules than the cannonball. Air resistance slows it down. If we did the same experiment on the moon (no air) what would happen? They would hit at the same time. Can you think of some ways we use air resistance? Parachutes are one way, by dramatically increasing your area with the parachute, you can slow yourself down to a speed where you can land without injury.