Today’s Wonder of the Day was inspired by Anthony . Anthony Wonders, “How do parachutes work?” Thanks for WONDERing with us, Anthony !
Would you like to visit the South Pole before you die? Put it on your bucket list! What about hiking the length of the Appalachian Trail or the Pacific Crest Trail? Those two trails are at the top of many bucket lists for sure.
Another popular bucket list item is to do something and maybe even death-defying. How about jumping out of a plane thousands of feet above Earth? That's right! Skydiving is certainly a popular item near the top of many bucket lists.
Have you ever thought about what it would be like to ascend thousands of feet into the air and then jump into nothingness to feel what it's like to fly back toward Earth? We're sure it must be a rush unlike any other.
Once you reach terminal velocity and Earth is getting closer and closer, you'll probably begin to worry about how quickly Earth is approaching. Have no fear, though. All you need to do is pull the ripcord to launch your parachute. Once it unfolds, it'll slow your descent, allowing you to touch down safely on Earth rather than hurtling to a certain death!
Exactly how does a parachute work? If you've ever seen a parachute, you know it just consists of a large piece of fabric with strings that attach it to a skydiver. There's no motor or propellers to lift you into the sky. How does a big piece of fabric stop you from crashing into Earth?
As you probably already know, the force pulling you toward Earth is gravity. Gravity pulls on all objects equally, yet some objects fall more quickly than others. Why is that?
It all depends upon the properties of the falling object. Certain properties allow a falling object to fight its way past all those molecules of air standing between it and Earth. For example, a heavier object will tend to push past those pesky air molecules more quickly than a lighter one.
A broad, flat object, on the other hand, will tend to fall more slowly than a narrow, round one. This is because a broad, flat object has a greater surface area for air molecules to push against. You can test this principle for yourself. Drop a regular piece of paper and a piece of paper crumpled up into a ball at the same time. Notice how much faster the crumpled piece of paper falls to the ground?
The force working against gravity that a parachute takes advantage of is called air resistance or drag. When a skydiver releases a parachute, it unfolds and quickly traps air molecules, effectively increasing the amount of air resistance and slowing the skydiver to a safe descent speed.
The larger the parachute, the more surface area it will have to trap air molecules and the greater its drag will be. This is why parachutes can be used to slow the descent of more than just skydivers. The military uses parachutes to deliver supplies and cargo to troops in remote areas. Parachutes are also used by drag racers to slow their cars at the end of a race.
Although it might seem like the parachute is probably a relatively recent invention since the airplane didn't come about until the early 20th century, it's actually quite old. Historians point to late-15th-century manuscripts that contained drawings of a parachute-type device. Leonardo da Vinci also sketched a parachute prototype.
Some believe the device existed hundreds of years before these sketches, though. Some historians believe Chinese acrobats may have used small parachute-like devices to perform falling stunts as early as 90 B.C.