The Physics of Skydiving
By Paige Brown, Museum Blogger-in-Residence
For those of us brave enough to skydive, we might want to know at what point during the dive we are going to be accelerating the most. Acceleration, after all, which is a change in velocity over time, is the source of the G-forces, described in multiples of gravity, that are notorious for making race-car drivers feel dizzy, or even causing high-speed jet pilots to faint.
Acceleration = Δvelocity / Δtime
If a human body is accelerating too quickly in the upward direction, blood can have a difficult time reaching the brain. This effect can produce tunnel vision if G-forces are large enough, because the eyes are losing out on oxygen and glucose normally delivered with blood.
If a human body is accelerating in the downward direction, on the other hand, blood is forced away from the extremities and into the head and eyes – think about standing on your hands, upside down.
So, when you are in that airplane, trying to prepare to be hurled out into the clouds, (actually, the typical jump is from about 13,000 feet in altitude, and many skydiving groups won’t go above cloud-level), you might want to be ready for points of high acceleration, or G-force, during the dive.
As it happens, you’re in luck, because a brave group of science film-makers jumped out of a plane with special sensors just to find out at what point a skydiver accelerates the most during a dive! Is it when you first jump out of the plane? When you open your parachute? When you land?
Watch this video and find out!
As it turns out, you are accelerating the most when you pull open your parachute! In this case, your body is slowing down at an average rate of 27 meters per second, per second, according to data collected by Rob Nelson. That is nearly a force of 3 G’s, or 2.75 times standard gravity!
Ready to go skydiving? Brace for the parachute opening!
Rob Nelson of Untamed Science gave a talk at the Daily Planet theater today about the physics of skydiving and other projects his group Untamed Science are working on! Be sure to check the Daily Planet talk schedule to hear from other awesome scientists and science communicators!