How long does it take to hit the ground from 4000 feet?

Talk About It Here!

MythMod

BUSTED! And so is the dummy! Ouch... well, newly defined Point Break!

would you really split apart if you fell like that?

isn't the time it took the dummy to fall inaccurate to the movie?
-It is free fall but in the movie, wouldn't the man's body position cause air resistance thus causing him to spend more time in the air?

Since I don't have a copy of the movie in front of me, I was only able to find one transcript online of the movie.
http://www.awesomefilm.com/script/pointbreak.html

There is says Bodhi told the pilot to climb to 8000 feet. But I haven't been able to find a second source to confirm that.

Bodhi did indeed tell the pilot to take the plane up to 8000 feet before he and roach exited.

Another copy of the script can be found here.

http://www.godamongdirectors.com/scripts/pointbreak.txt

I have seen this movie about 12000 times and I knew immediately that 4000 feet was wrong. While this won't make the freefall 90+ seconds it will at least double it.

The last myth was confirmed but would be even easier with an additional 4000 feet to catch up.

Good job as always just came up a tad short on a minor detail.

Ok technically didn't the third test for the free fall. (the catch up) discredit the
first.?

Since the dummy did not attempt to slow down his fall the way swazye did? By strectching out it's (aka posing the dummy's) body

Tey should ahve strapped a set of weights to the "simuloid" and set it's boidy in the right position instead they just dropped it?
All it appeared to me they proved was the concept of inertia

Also why did they have a second skydiver in the second part (mid air conversation) wouldn't they just need to have him talk to the guy he was strapped too. Since technically, that was the same position the 2 were in in point break?

I would say they would have to revist this myth again?

first off, always a great show. been a fan since the beginning...
but there is a simpler way. instead of wasting the time, money, fuel, etc., it would have been a lot easier to calculate approximately how long it would take to hit the ground rather than push a dummy out the door. just calculate the 9.8 m/sec/sec acceleration due to gravity, and you would be able to arrive at the answer. but, i do realize that it wouldnt make for a good show. no one would want to watch grant sitting at a table doing math.

also, doubling the distance of the fall would not necessarily double the fall time. you would keep increasing speed every second you are falling, up to the terminal velocity.

plus, from 4000 feet, wind resistance would not necessarily slow you down enough to negate the experiment using a flimsy dummy. it would only be literally a matter of seconds difference.

thanks mythbusters, and keep up the good work.

The wind resistance on the 4000 ft. fall would slow you down if you were in a normal sky diving position. (A level body)

Please revisit this myth,this is an awsome show

doing some quick calculations on it, terminal velocity is about 176 ft/sec for a free falling human-this is reached in about 6 seconds of falling. it would then take approx 25 seconds to fall 4000 feet, and about 48 seconds to fall 8000 feet.

i have heard somewhere that it is possible to live from a large fall, as long as you land flat on your back. something about dispersing the force of impact throughout your entire body. this would then probably break every bone in your body, and would probably die soon afterward. but the myth is that you would live after the impact. anyone heard this?

Just one thing to note, the freefall in the movie isn't necessarily 90 seconds (I mean, even disregarding how far that actual stuntmen were falling for) because of how it cuts back and forth to different views. Going from cut to cut and view to view doesn't necessarily imply that all these shots happened one after the other, that you can add up all the freefall time and arrive at 90 seconds. If you see 5 seconds of them locked up from a closeup, and then 5 seconds after that of them locked up from a wide shot, that could mean that they have been falling for EITHER a total of 5 seconds or 10 seconds.

A similar situation would be movies where someone difuses a timed bomb. The timer says 10 seconds but the movie time as it counts down is often much longer because it's not showing the countdown and the things that are happening simultaneously with the countown on the screen at the same time.

Anyway, it's rather pointless to argue, since it's a movie.

And rather pointless for the mythbusters to test anyway. They might as well pick some movie that shows a person getting on a plane in New York, and then cuts to a scene of them getting off in Paris 5 seconds later.

CAN YOU CROSS THE ATLANTIC IN 5 SECONDS! THE MYTHBUSTERS ARE ON THE CASE!

Movies use editing to extend and compress time... what is the point of "testing" these "myths?"

what i want to know is "where's buster"? that free fall should have been done by buster, not some pansy simuloid with what i can only discribe as firecracers for guts.

Yeah the way the dummy was moving all over the place does not create the best test.
They really need to have the person in a jump suit, parachute, and staying steady in the standard jump form.

Just as you can pull your arms in and dive forward to go faster the dummy would have been going faster then a person would staying steady.

Revisit time!

quote:

Originally posted by Elysium2:
And rather pointless for the mythbusters to test anyway. They might as well pick some movie that shows a person getting on a plane in New York, and then cuts to a scene of them getting off in Paris 5 seconds later.

CAN YOU CROSS THE ATLANTIC IN 5 SECONDS! THE MYTHBUSTERS ARE ON THE CASE!

Movies use editing to extend and compress time... what is the point of "testing" these "myths?"

I pretty much agree. Testing the basic concepts found in movies is a good idea but I don't think being that specific about it is necessary.

The answer was actually given in the episode itself, in another section. When Kari and Tory were testing the differences in wind resistance - Tory with a high-drag pose and Kari with a low-drag pose, they gave terminal velocities for both. Tory's terminal velocity was stated to be ~120 MPH. Kari's was ~250 MPH.

An object in free fall will naturally find its most aerodynamic position.

examples:
An arrow tossed end over end into the air will right itself.

I enjoy tossing water bottles REALLY high and catching them, and even a filled water bottle will do this after only about 30 feet of free fall.

That being said, the dummy's free fall is going to be close to (although a bit slower, granted) that of Kari, @ 250 MPH. In Point Break, Swazey was in a high-drag pose, going 120 MPH (like Tory).

Disclaimer: Now, I can't recall off hand, but I think they said it took the dummy 32 seconds to fall - if I'm wrong, just correct my numbers. I also know that terminal velocity is reached fairly quickly, but not not exactly proportional, but it's late, so that being said...

Say the dummy was 10MPH slower than Kari's terminal velocity - 240MPH - it would have taken Swazey twice the time to descend, putting it at 64 seconds, not 32 seconds - which while still busted, is off by a factor of 2.

This is my first post here, so I hope this isn't out of the normal style - I just thought I'd join in after watching for years and years.

in the myth on the new episode about a 90 second free fall that eventually go busted could be plausible!!! If you are flying in a high altitude area at 4000 feet above the ground, your aircraft is set to the ground level. But if you are landing at an area at sea level you need the ATC to tell you what the ground level is at. You need to be flying at IFR or instrument flight rules or be about to land to be told that. So, if you are coming from a place that is 5000 ft above sea level and come into a place that is 1000 ft, you would be at 8000 feet!! Which could take more that 90 seconds to hit the ground!

Good first post Nate. I hadn't finished watching the episode myself when I wrote and saw they were answering the question in that simulator free fall chamber too.

I also saw something else the Mythbusters should look at for a revisit, the location.
In the movie it shows them over a desert and the Mythterns were over farmland.
The problem? Updraft of the warm air of the desert heat can be quite powerful.
Seeing the tests done over a desert area would be great.

Omg, they forgot to test another part of this myth. They falling for so long when the opened the parachute, would the parachute slow them down in time?

There two myths from the Point Break scene they did not test:

1. if the second skydiver could catch the first would it be possible to hang on when the parachute opened?

2. Would a standard parachute of the type used support that much weight?