Question

Why did felix baumgartner fall from a higher height than kittinger, but acheive a lower terminal velocity?

Answer 1

Sorry, I mean free fall for less time, not achieve a lower terminal velocity

Answer 2

Pulled his 'chute sooner?

Answer 3

of course! im an idiot

Answer 4

It might be something else, but that seems most likely.

Answer 5

I'm working on it, but more than likely its pulling the chute sooner.

Answer 6

Possibly because he fell from a greater height, he had more velocity than kittinger, and so his duration of fall was less?

Answer 7

Starting from a greater height, the air resistance is less, but so is the gravitational acceleration.
The decrease in gravitational acceleration isn't very much though.
The increase in velocity due to less air resistance probably helped out a bit to decrease the time, but since Felix had a choice when to pull the cord, the time of free fall was really up to him.

Answer 8

Yeah i guess. epic to watch!

Answer 9

Seriously. I've seen sky dives before and they are over in a few seconds, he fell for minutes before I even recognized that there was ground underneath him!

Answer 10

yeah, started spinning too. Stepping out onto that ledge was awesome.

Answer 11

So I think I have a good idea of what the answer is. Basically what you do is set up a free body diagram force downward is mg force upward is -bv^2, negative because it opposes the motion. The constant b depends on many things. For a person is going to be b = 0.5pAC. p is density, A is area, C is drag coefficient.

You reach terminal velocity when your acceleration is zero. So all you have to do is sum the forces and set it equal to ma and then set a = 0 and solve for v.

Now, when you look at what your terminal velocity equals, you notice that it depends on many different constants.

Lets look at each one and talk about it.

Mass - I don't know if you can assume Felix and Kittinger have the same mass, but obviously in real life their masses probably won't be exactly the same.

G - Acceleration due to gravity, depending on how high Felix is from Kittinger g will vary, but probably not my much. As you increase in height gravitational acceleration decreases.

reference: http://physics.learnhub.com/lesson/10735-change-of-gravitational-acceleration-due-to-height

C and A - Drag and area. These depend upon the person/objects shape. We know that while skydiving that you can be belly down (falling flat) or head down (falling at an incline face first). So the size and shape that you curl yourself into matters.

p - Density, higher altitudes means lesser density.

So to actually answer your question, I would say that the reason why he achieved a lower terminal velocity was because of these following constants, but we actually don't know what shape he fell in or how high he was, but he did have a lower terminal velocity so these constants must have had the correct values so that when you calculate them in the formula his terminal velocity was lower than Kittinger's.

So terminal velocity depends on these constants, he must have had the right conditions or constants such that his terminal velocity was lower than Kittinger's.

Answer 12

http://en.wikipedia.org/wiki/Terminal_velocity

Answer 13

Thanks, great answer! but i rephrased my question to "why did Felix freefall for less duration" Still really great response fellowroot :)