What Does Terminal Velocity Mean In Skydiving?
When people talk about tandem skydiving and jumping out of an airplane, one number they’ll often mention is 120mph. Is this true? The answer is. kind of.
Terminal velocity means the top speed an object can achieve when it falls through the air. While gravity is a constant force, terminal velocity is not – it is created and affected by a few different things.
The weight and density of an object speed it up. The shape of the object, and the drag it creates as it falls, slows it down. And the combined result is the object’s terminal velocity.
How this works in tandem skydiving is that people equip themselves correctly and train to manipulate their body position so they can go at the same speed. Skydiving on your own is great, especially at Skydive OC but getting together with you friends in freefall is even better.
Smaller skydivers wear tight fitting suits to create less drag, or even wear extra weight to add speed. Larger skydivers wear baggy suits and fly their bodies in positions to create more drag and go slower. This is where the number 120 mph is used, as it is considered the approximate average terminal velocity of a skydiver.
When you jump out of a skydiving plane, terminal velocity isn’t immediately achieved – it takes a little time. At the instant you first jump out you are actually thrown forward on the same trajectory as the plane (that is going forwards at around 100mph). Over the course of the next 10 seconds, this forward momentum is overtaken by the effect of gravity as you travel on a big graceful arc into freefall. This is referred to in skydiving as “going down the hill” as it visualizes a curve.
Skydivers do things in different ways, and depending on this it affects their average terminal velocity. While flying face-down, jumpers indeed have an average terminal velocity of 120 mph, but if they are ‘freeflying’ – which means adapting your body position to fly in other orientations such as ‘head-up’ and ‘head-down’ – the average terminal velocity is more like 160mph. Speed skydiving is where people point their head directly at the ground and streamline their body as much as possible in an attempt to go as fast as they can, which can reach over 370mph!
The current record holder of both the highest jump and fastest freefall speed is Alan Eustace. In 2014 Eustace jumped from a big balloon at 123,414ft and broke the sound barrier on the way down with a top speed of 822mph. He achieved this speed falling on his belly to remain stable, and was able to do so because the higher up you go the thinner the air gets creating less drag.
So terminal velocity is not a single set speed and can be affected by various factors. The speed 120 mph is what you hear most because it is kind of true and is a nice round number that people have a frame of reference for.
The really important thing to understand about jumping from an aircraft and falling towards the earth at terminal velocity is how it feels. There is something particularly exciting about the skydiving sensation of speed created from gravity alone that separates it from other experiences where you go fast for thrills. When you do jump it just feels right, and is the most natural and freeing sensation – like your whole life has been building up to this moment. What are you waiting for? Join us for a jump and find out for yourself!
Terminal Velocity in Skydiving
Ah, the study of the physics of skydiving: the practicum of which presents the world’s most bombastic science field trip. On paper, calculating the terminal velocity in skydiving looks kinda like this:
How fast does a skydiver – who clocks in at X total weight – fall at X landing altitude in X weather conditions when he/she adopts X body position?
As you can see, it’s a titch more complicated than the “120 miles per hour!” the internet usually offers when you ask how fast you fall when you’re skydiving. If it’s a surprise that you actually get a choice – lean in.
1. Want a simple answer? Design a simple situation.
Terminal velocity physics — as with most things scientific — gets simpler when fewer variables are involved. That, indeed, is where the internet got its reductionist approach: from the fact that most tandem pairs are comparable enough in size, and adopt a comparable enough body position once they’ve hit their airborne stride, to be more-or-less comparable at large. That’s why it’s a commonly thrown-around figure that the average terminal velocity for skydiving hangs out at about 120 miles per hour. It’s a solid average for a related group, and it’s a nice, clean number.
Another reason 120mph is significant that you can test it for yourself – if you can find a big enough fan: 120 miles per hour is also the precise wind speed at which a standing person loses the ability to stay upright and in one place. (Check out XKCD for the visual on that.)
2. Terminal velocity in the sky, on a cloudless day, doesn’t feel as fast as terminal velocity does when you pass a cloud.
Ready to check the way terminal velocity physics works in real life versus how terminal velocity physics works in the context of your imagination? Book two tandem skydives: One, on a day with a few clouds floating around, and the other on a day that’s totally bluebird. This’ll kinda blow your mind.
Try to make your first jump on a cloudless day. Sure, you’ll be as full of butterflies as a bag of rotting fruit in the middle of the Amazon, but you’ll certainly be able to remember at least one thing about your experience: that you don’t feel like you’re hurtling down at 120 mph. Unimpeded by visual references, with the world spread out like a map beneath you, you’ll hear the wind, but you won’t feel like a dog with its head out the window on a Nascar track.
If you’re lucky enough to pick a day for your second jump that offers a couple of puffies for perspective, you’ll be very surprised. When you pass a cloud on the way down, your true speed is revealed. (And boy howdy is that fun.)
3. Skydiving terminal velocity can change depending on the shape you make.
Once you’re a sport skydiver, you have some choices when it comes to terminal velocity on any given skydive. The shape you make — whether that’s the shape you show up in, or the acrobatic maneuvers you perform, or the kind of suit you wear — factors in heavily.
Heaviness, indeed, is a thing: Heavier folks fall faster. Jumpers in baggier clothing fall slower, because of the extra drag. Body position is a much bigger deal; the more surface area you present to the wind, the slower you go. (Speed skydivers try to point the crown of their head directly at the ground. That kind of skydive is over a little too fast for our taste, but they make for some pretty amazing records.)
Got more questions? Don’t be shy! We’re happy to answer them for you. Just ask!
How Fast & Long Do You Fall When Tandem Skydiving?
If you want the short answer: really, really fast. About 120 mph (200 kph)!
Now, if you’ve got a thirst for knowledge as great as your need for speed, we’d love to get nerdy and give you the nitty-gritty details of exactly how fast you will fall when tandem skydiving. Be prepared, it’s going to take a bit of patience on your part and a willingness to revisit a bit of physics knowledge we bet you thought you would never need.
How Fast Is Freefall?
For a tandem skydiver, the fastest part of your skydiving experience is the freefall. As you may have guessed, freefall is the time between when you exit the airplane and when you deploy your parachute. During this time, you are falling free, but not necessarily freefalling! The reason is semantics: technically, the physics definition of freefall is the downward movement of an object under the force of gravity alone.
As a tandem pair falls, the force of gravity acts upon them but so does something else. Though, it may seem like the air is “empty,” it is composed of many invisible air molecules. As the tandem skydiving pair falls, they collide with these particles, and the air particles are pushed aside much like a swimmer pushing his or her way through the water. The collision with these air particles creates air resistance (or drag) and prevents the falling object from infinitely increasing speed. So, your ultimate speed has to do with something called terminal velocity.
What Is Terminal Velocity?
So, how fast do you fall when skydiving? In part, this will depend upon the amount of air resistance you encounter. By definition, terminal velocity is a constant speed which is reached when the falling object is met with enough resistance to prevent further acceleration. Terminal velocity is, then, the fastest speed you will reach on your skydive; this is usually around 120 mph.
Do you feel your stomach drop when you skydive?
The cool thing about your skydiving freefall is that it doesn’t feel like falling, so you typically won’t get that stomach drop feeling. Though you are reaching terminal velocity at a speed of 120 mph, because of the air resistance you encounter, it will feel more akin to floating than falling. Additionally, the airplane you will be riding in prior to your skydive will be moving at speeds around 100 mph. Usually, the stomach drop feeling can be attributed to extreme changes in speed. However, the change in speed from your plane ride to freefall is not extreme enough to cause much of a stomach drop. Typically, upon initially exiting the airplane at 10,000 feet you will feel a bit of a speed increase, as it will take around 5-10 seconds for you to reach terminal velocity. But you won’t experience a stomach drop like on a roller coaster.
How long do you fall when skydiving?
The amount of time you fall when skydiving is going to depend on two things: how long it takes you to reach terminal velocity and the altitude you jump from. At Skydive St. Louis, you will make your jump from 10,000 feet which is nearly two miles above the earth. From this height, you will fall for 45 seconds.
Ready to speed through the wild blue yonder at 120 mph? Reach out to Skydive STL and book your first skydive today!