Have you ever watched a milkweed seed, a bit of cottonwood fluff, or a feather float through the air? We know that gravity is always present, pulling any object that goes up back down. Why do these objects seem to take a long time to reach the ground though? It’s not because they’re light, although that helps. They float because they fluff or branch out, creating resistance to the air.
Parachutes work on the same principle. We can’t see air, but it takes up space just like water. Think about walking through water. If you walked with your hands at your side, you could move fairly easily. Put your arms out and spread your hands though and the water becomes more difficult to walk through. Your hands create resistance. A parachute does the same thing in air. As it expands, it creates resistance to the air and slows your fall.
- Any time a force pulls on another object, the object moves. When you jump out of a plane, the force of gravity immediately begins to pull you, speeding up your fall, which is known as acceleration. Without a parachute, you’d fall at about 125 mph. Ouch!
- A parachute slows your fall to about 12 mph – enough for a much safer landing.
- A parachute is bundled into a package called the container, which actually contains 3 parachutes – the main parachute, a back-up or reserve parachute, in case the main parachute doesn’t open, and a pilot parachute. The small pilot parachute opens first and pulls the main parachute out.
- NASA used a parachute to safely land and stop the Space Shuttle.
- Force: Interaction that changes the motion or direction of an object
- Resistance: Acts in the opposite direction of a force moving an object
- Acceleration: When a force causes an object to speed up or move faster
Q and A
Question: Do heavy things fall faster than lighter things?
Answer: It seems logical to expect that they would, but if you dropped a rock and a feather in a vacuum where there is no air pressure and no air resistance, they both would reach the bottom at the same time. In the real world, though, heavy things often do fall more quickly than lighter things, depending on air resistance. Experiment with dropping different objects to learn more.
Visit Mocomi Kids to watch a demonstration of parachutes and air resistance.
Watch Mister Stapleton make a parachute; then make one of your own.