Free falling at 1500 km/h

[alf101]

http://technology.iafrica.com/news/science/726470.htm

Tue, 22 Apr 2008 07:26
A 64-year-old retired French army parachutist said on Monday he hopes to smash through the sound barrier with a record-breaking 40 000-metre freefall jump over Canada next month.

Michel Fournier hopes to set four new world records at once: for highest freefall parachute speed, at 1500 kilometres per hour, 1.3 times the speed of sound, along with fastest and highest jump and highest air balloon flight.

The Russian Evgeny Andreyev made the highest recorded parachute jump with a 24 483-metre plunge in 1960, while the American Joseph Kittinger claimed an unverified jump of 31 000 metres in 1960.

The veteran French parachutist will take off on 25 May from the Canadian province of Saskatchewan in a pressurised capsule, harnessed to a 161-metre helium-powered balloon, rising to almost four times the height of an airline flight.

Pressure will be let off gradually to allow him to exit and make his jump, wearing a specially-developed protective suit with two oxygen bottles, in conditions similar to an astronaut leaving his spacecraft.

Fournier told a press conference in Paris his jump would have "considerable repercussions for aeronautics and space, for medicine and high-technology".

French astronaut Jean-Francois Clervoy, who is sponsoring the project, said it could help shed new light on the behaviour of the human body at the speed of sound, with potential applications for future rescue operations in space.

The French army piloted a similar project in the 1980s, aimed at developing an ejector capsule for European spacecraft, in which Fournier was due to take part before it was finally aborted.

With more than 8600 jumps to his name, Fournier holds the French height record at 12 000 metres.

His project, which drew teams of specialists in high-altitude and underwater conditions, spacesuits and extreme condition health experts, cost €11.8-million.

[dovij]

I thought terminal velocoty is something like 130m.s-1?

[Balstrome]

I thought terminal velocoty is something like 130m.s-1?

Not if you apply lots of grease:p

[Messugga]

Which is exactly why he'll have to drop is drag-coefficient a LOT. Wonder how they're going to manage it.

[Devill]

that depends on weight and effective space that could be calculated into wind/air resistance.....thus a feather has avery low ter. vol. and an a ball of lead has a high one (because its ration between weight/space taken up, high)

[alf101]

He's been trying it since 2002 I think.
Looks like a fun thing to do.

He's falling from 40km up, so he can go rather fast, like a space shuttle.

[Messugga]

alf, the height isn't the major thing. If you jumped from 10k feet, you'd reach terminal velocity way before reaching the ground. As your velocity increases, your drag increases as well, but exponentially. When drag = force applied by gravity, you stop accelerating. That's called terminal velocity. If they can somehow drop his drag coefficient by placing him in some form of capsule or some such, he'd be able to go faster.

[Devill]

He's been trying it since 2002 I think.
Looks like a fun thing to do.

He's falling from 40km up, so he can go rather fast, like a space shuttle.

doesnt matter from how far up you go....terminal velocity is te speed / displacment speed limit :)

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

also....

The terminal velocity of a falling body occurs during free fall when a falling body experiences zero acceleration. This is because of the retarding force known as air resistance. Air resistance exists because air molecules collide into a falling body creating an upward force opposite gravity. This upward force will eventually balance the falling body's weight. It will continue to fall at constant velocity known as the terminal velocity.

[xrapidx]

doesnt matter from how far up you go....terminal velocity is te speed / displacment speed limit :)

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

also....

The terminal velocity of a falling body occurs during free fall when a falling body experiences zero acceleration. This is because of the retarding force known as air resistance. Air resistance exists because air molecules collide into a falling body creating an upward force opposite gravity. This upward force will eventually balance the falling body's weight. It will continue to fall at constant velocity known as the terminal velocity.

The air is thinner at 40km, surely that makes a difference.

[Valis]

Erm, at that height there isn't much air to create drag. Thus, the two oxygen cylinders.

Edit: xrapidx beat me to it :-)

[Devill]

The air is thinner at 40km, surely that makes a difference.

not that much (.....and also he is coming down to where the air is more dense again :p

Although air is well mixed throughout the atmosphere, the atmosphere itself is not physically uniform but has significant variations in temperature and pressure with altitude, which define a number of atmospheric layers. These include the troposphere (0 to 16 km), stratosphere (16 to 50 km), mesosphere (50 to 80km) and thermosphere (80 to 640km)

Maybe he should go up to 20 000m :p

THAT myth is Busted!!

[DJ...]

Can you imgine how pissed he is gonna be if he succeeds in his quest for 1500km/hr and his parachute doesnt open. Come to think about it: What is his parachute going to be made out of to deccelerate him from 1500km/hr!!!??? Unless he changes body position to deccelerate to normal parachute speeds, in which case I wish him all the best, lunatic!

[Messugga]

And the suit because at 40km, water boils at room temperature ;)
v =ut + 0.5at^2
1 500 000 = 0.5(9.8)t^2
t = (2 x 1 500 000)^-0.5
= 1732.05 seconds
= 28 minutes to get to that speed when accelerating at 9.8m.s^-1, which is what we do at earth's surface. 40km up, it's a fair amount less. Something sounds a bit wrong.

[Devill]

lol...thats why they spent almost 12 mill euros on the project :p

else im sure they would have asked us arm chair physicists to do the calculations :)

[alf101]

And the suit because at 40km, water boils at room temperature ;)
v =ut + 0.5at^2
1 500 000 = 0.5(9.8)t^2
t = (2 x 1 500 000)^-0.5
= 1732.05 seconds
= 28 minutes to get to that speed when accelerating at 9.8m.s^-1, which is what we do at earth's surface. 40km up, it's a fair amount less. Something sounds a bit wrong.

Google "Michel Fournier" a bit, fair amount of articles since 2002.

http://www.instablogsimages.com/images/2007/08/14/michel-fournier_1822.jpg

[Messugga]

alf, I'll take your word for it. The only conclusion I can make though is that he uses some form of rocket propulsion to aid in acceleration.

[alf101]

alf, I'll take your word for it. The only conclusion I can make though is that he uses some form of rocket propulsion to aid in acceleration.

Added a pic.
Don't know how if he'll get it right, but it's on May 25th.

[Valis]

And the suit because at 40km, water boils at room temperature ;)
v =ut + 0.5at^2
1 500 000 = 0.5(9.8)t^2
t = (2 x 1 500 000)^-0.5
= 1732.05 seconds
= 28 minutes to get to that speed when accelerating at 9.8m.s^-1, which is what we do at earth's surface. 40km up, it's a fair amount less. Something sounds a bit wrong.

You forgot to divide by 9,8. Actually takes about 9 minutes.

Edit: Whoops! Totally wrong equation ;-)

[Messugga]

Ah, I thought I made a mistake somewhere ;) 9 minutes sounds much more feasible. Still, respect if he manages it.

[Devill]

Added a pic.
Don't know how if he'll get it right, but it's on May 25th.

soz am i just a bit slow? (100% possible today :) ) but where is the pic you added?

[alf101]

In post #15, u got no international left?

[Devill]

no just to lazy :p

add a link where you say "added a link ..lol

[alf101]

no just to lazy :p

add a link where you say "added a link ..lol

http://mybroadband.co.za/photos/showphoto.php?photo=3608&cat=500

[DJ...]

alf, I'll take your word for it. The only conclusion I can make though is that he uses some form of rocket propulsion to aid in acceleration.

Maybe thats what the oxygen tanks are really for:D

[Devill]

thats more like it :)

cant see any rocket propelled help.

Wonder how it will be done :confused::confused::confused:

[alf101]

thats more like it :)

cant see any rocket propelled help.

Wonder how it will be done :confused::confused::confused:

F knows.
They aren't called vleis bomme for nothing.

[Valis]

Ok, just worked it out correctly. Disregarding air resistance, it will take 42 seconds to reach 1500 km/h. From rest, that means he'll be falling for about 8857 meters. Starting at 40 000 m gives plenty of leeway. I'm not sure what the air resistance is at that altitude, but I imagine it's negligible.

Saw a program about a guy going for the hang-gliding altitude record once. He fell for a few kms before there was enough air resistance for the aerodynamic properties of the hang-glider to start working.

[Just_Ice]

And the suit because at 40km, water boils at room temperature ;)
v =ut + 0.5at^2
1 500 000 = 0.5(9.8)t^2
t = (2 x 1 500 000)^-0.5
= 1732.05 seconds
= 28 minutes to get to that speed when accelerating at 9.8m.s^-1, which is what we do at earth's surface. 40km up, it's a fair amount less. Something sounds a bit wrong.Please note that in the new curriculum we now use vf instead if v, and vi instead of u! :p seriously though, this parachute needs to go learn about newton and his laws!

[alf101]

Think I should've posted this in the science section rather.

Then have it moved to the PD section later.

[Valis]

Think I should've posted this in the science section rather.

Then have it moved to the PD section later.

LOL!

[Messugga]

Please note that in the new curriculum we now use vf instead if v, and vi instead of u! :p

Well, that's how we wrote it in uni and so, that's how I'll continue writing it :p

[Devill]

Well, that's how we wrote it in uni and so, that's how I'll continue writing it :p

What physics book did you use?

[Just_Ice]

What physics book did you use?
An old one I rate. lol

[dablakmark8]

A real mad man.

[Alan]

Good luck to him he's going to need it.

Joseph Kittinger's jump

http://www.youtube.com/watch?v=81gn2oLeC_U

[Messugga]

What physics book did you use?

Fundamentals of physics, back when I did mechanics. That was in first year though. Only did up until physics 2. Electronics was fun. Electrodynamics...not really as much. The math turned all bleh.

[Pyro]

Remember using v and u in school days, but varsity you could use any damn thing you wanted as long as you were consistent in your usage.

v-initial and v-final makes the most sense though, so your vi and vf makes the most sense in that case. v0 and v1 for phases of acceleration would also make sense...

[Devill]

Fundamentals of physics, back when I did mechanics. That was in third year though. Only did up until physics 2. Electronics was fun. Electrodynamics...not really as much. The math turned all bleh.

Halliday, Resnick and Walker : Fundamentals of physics is a good book :)

I hope this guy (the jumper) is got his things in order because you dont want your family to fight over the bits and pieces :p

[Messugga]

Meh, meant to say I did mechanics in first year, not third year :) I wonder how much would be left if he hit the ground at that velocity? Would be funny if the Mythbusters guys could soup up that chicken cannon they used on the aircraft windshield, so that it shoots at 1500km/h instead of the several hundred kilometers it did originally :D