I haven’t been skydiving before, but I have a good orientation balance. I’m curious if the movie, cartoon, etc. scenes where someone points themselves downwards to be more “aerodynamic” actually increases their speed during fall time compared to people spreading eagle or flailing, or if that’s just a movie thing that “looks cool”.
I tried to look this up but current Google and the AI responses are rough to try to parse through. Thanks!
CLARIFICATION EDIT:
I was wondering after terminal velocity is reached for a free fall/skydive, but I’m seeing a ton of great answers on how that does work even after!
Comments
Yeah. It does. You weigh the same either way, but spread out and flat your body catches much more air to slow you down.
Now, how much of a speed increase, I haven’t exactly tested. Google suggests it can make a difference of around fifty mph.
Yes. Watch people skydiving indoors, that’s how they control their elevation
Go grab a piece of paper, make sure it’s flat and drop it. It drops slow because there’s a lot of air it’s pushing through
Crumple the paper, it falls faster because there’s less air.
This is what drag is
The longer and higher you fall the more important drag becomes, big fast military jets that need to go really fast are like pencils (look up the F-104 Starfighter)
Yes one of the variables in the terminal velocity equation is your drag coefficient which is directly related to your cross-sectional area through the air.
Spreading out body = huge area = high drag
Tucking like a pencil = small area = low drag
The force of air resistance is proportional to the surface area of an object moving through air. That’s how parachutes and wing suits work. They give a falling person more surface area.
The same is true even for the position of your body. You can have more surface area if you splay your limbs and orient your torso parallel to the ground
tl;dr – yes
Mythbusters actually did a segment on this from the movie point break where Keanu waits before jumping out of the plane with no parachute, goes in to a dive to catch up with the skydivers.
They were surprised when even waiting on the plane for a bit before jumping as it was done on the movie the jumper was still able to catch up with the original person.
When falling your terminal velocity is decreased because of the excessive resistance from being spread out. If you go into a diving motion you drastically decrease your cross section so you go faster. There will be a point where you will hit your new maximum speed but it will be faster than someone with a larger cross section.
Yes.
Your terminal velocity while falling depends on two forces acting on you: gravity and air resistance. Gravity pulls you down, and air resistance acts against movement (so in this case, pushes you up).
You can’t really change how much gravity pulls you down (unless you’re carrying something heavy which you throw away mid-fall), but you can influence air resistance. Air resistance depends on your surface area – if you’re “wider”, you have to push more air out of the way as you fall, so air resistance is greater; if you’re “thinner” you hit less air, so air resistance is lesser.
Orienting yourself vertically makes you “thinner”, so less air resistance, so you fall faster. On the other hand, orienting yourself horizontally makes you “fatter”, slowing you down. The extreme of this is using a parachute, which massively increases your surface area (therefore massively raising air resistance) hopefully slowing you down enough that you don’t die at the end of the fall.
It makes a large difference; the drag changes. Both the cross-sectional area and drag coefficient decrease. The maximum speed you can fall at is called terminal velocity. This is when the drag from the air equals the force of gravity.
Drag force = 1/2 * speed^2 * cross-sectional area * drag coefficient * density of the air.
Gravity force = mass * gravitational constant
The result is that at constant mass, if the cross-sectional area and/or drag coefficient decrease the speed increases.
We talk about 200km/h belly down compared to 240-290 km/h head down close to Earth’s surface.
The reason Felix Baumgartner has the skydiving speed record is that he jumped from 39km altitude, where the density if air is lower. As a result, he broke the speed of sound and fell at an estimated 1,357 km/h
Think of birds of prey (peregrine falcon for this instance). Birds that can fly basically sort of float on hot air. They spread out their wings and bodies to catch air and “stop” their descent. When the peregrine falcon (or insert your personal favorite bird of prey), which is the fastest bird, goes to hunt, it points itself to directly line up with its prey and tucks its wings and body into the smallest package it can to minimize wind resistance and get the most speed. After it hits/misses its prey, it immediately spreads its wings to slow descent and change course nearly immediately.
If birds of prey didn’t do the last part, we wouldn’t have any birds of prey. Every single one would be a feather pancake on their first hunt.
*mumblemumble terminal velocity mumblemumble*