2 helicopter question

2007-01-03 11:32:00

#1

bobby177: Member; +129|6480|Texas.. getting out asap

If you took 2 helicopters to 1000 feet and flipped one upside down and stuck them together and turned on both their engines which way would they move?

I think they would stay where they are because both their engines are the same power

2007-01-03 11:33:23

#2

Archer: rapes face; +161|6430|Canuckistan

The opposite directions? As in repel, like magnets.

EDIT: This is assuming that the G force is reasonable.

Last edited by Archer (2007-01-03 11:34:22)

2007-01-03 11:33:30

#3

SaladForks: /ph34r; +129|6588|Eastern USA

They would fall. The pull of the one upright cant handle for the pull of the one propelling down and the pull of gravity. It would make them descent.

Last edited by SaladForks (2007-01-03 11:33:59)

2007-01-03 11:33:46

#4

Superior Mind: (not macbeth); +1,755|6699

just stop, no more "what if" questions PLEASE!

x

2007-01-03 11:34:16

#5

bobby177: Member; +129|6480|Texas.. getting out asap

Superior Mind wrote:
just stop, no more "what if" questions PLEASE!

Hey, if Mombassa can troll I can too

2007-01-03 13:36:37

#6

[RDH]Warlord: Quakecon Attendee; +17|6665|SLC, Utah, USA

Fall. The first one's barely able to keep it upright as-is, let alone with another helicopter's dead weight on it, let alone the downwards pull of that second chopper.

Keep 'em coming!

2007-01-03 14:08:23

#7

Skorpy-chan: Member; +127|6351|Twyford, UK

Down. The one on top would be producing no lift, and the bottom one would not be able to support it in a hover.

2007-01-03 14:13:48

#8

bobby177: Member; +129|6480|Texas.. getting out asap

but they both push just as hard

2007-01-03 14:38:22

#9

Chuckles: Member; +32|6554

bobby177 wrote:
but they both push just as hard

That sounds dirty.

They may both "push" at the same rate, but the one that's upside down also has gravity helping it. They crash. If you ever get to try this experiment, stand directly under them and let us know how it works out.

Last edited by Chuckles (2007-01-03 14:39:22)

2007-01-03 14:39:14

#10

Entertayner: Member; +826|6577

Gravity would be the deciding factor, the downwards thrust on the one on top and the upward thrust on the one underneath would be equal however gravity would in theory increase the "thrust" from the upper one forcing the lower one down.. Or something like that.

2007-01-03 14:42:26

#11

Scorpion0x17: can detect anyone's visible post count...; +691|6772|Cambridge (UK)

yep, if the 2 helicopters are producing equal but opposite forces, then they cancel out and the only thing left is gravity - they would both fall out of the sky.

2007-01-03 14:43:23

#12

liquidat0r: wtf.; +2,223|6633|UK

They would go sideways. Once you get to a 1000 feet gravity starts to act sideways. It is a common misconception that gravity always acts downwards.

2007-01-03 14:44:25

#13

Scorpion0x17: can detect anyone's visible post count...; +691|6772|Cambridge (UK)

<*slaps liquidat0r with a wet mackrel*>

2007-01-03 14:44:25

#14

-=raska=-: Canada's French Frog; +123|6632|Quebec city, Canada

Ive feeling this thread will turn into a "Plane on a treadmill thread" style.

2007-01-03 14:45:35

#15

Dr_Paulos236: Member; +41|6402|England

Yeah precisely, they're both at the same rpm for the rotor blades or whatever, therefor they would hover if there was no gravity. Gravity will of course act in this situation at 9.81 ms-². So unless the top helicopter was faster than the bottom one, and could withstand the force of gravity they would hover.

Why do you ask anyway? This would never happen!

2007-01-03 14:46:22

#16

Chuckles: Member; +32|6554

-=raska=- wrote:
Ive feeling this thread will turn into a "Plane on a treadmill thread" style.

Let's hope it's closed soon. We're all dumber for having participated.

2007-01-03 14:46:45

#17

Hurricane: Banned; +1,153|6637|Washington, DC

bobby177 wrote:
Superior Mind wrote:
just stop, no more "what if" questions PLEASE!
Hey, if Mombassa can troll I can too

If the fad with teens these days was to see who can last the longest after taking a bunch of cyanide, would you do it cause everyone else does it?

To answer your question, the upright chopper would fall under the weight of the other chopper.

edit: No advanced physics involved. A chopper can't fly upside down for very long. It starts falling.

Last edited by Hurricane (2007-01-03 14:48:18)

2007-01-03 14:50:16

#18

Skorpy-chan: Member; +127|6351|Twyford, UK

bobby177 wrote:
but they both push just as hard

Helicopter rotor blades are just wings; they don't work upside down. Both of them have to work against gravity.

If you did this in zero gravity, yes, it would just have them stuck together until one slips. But there is gravity, and they would fall.

2007-01-03 14:55:44

#19

Microwave: _; +515|6661|Loughborough Uni / Leeds, UK

Gravity unbalances the forces.

2007-01-03 15:32:28

#20

Vub: The Power of Two; +188|6501|Sydney, Australia

Skorpy-chan wrote:
bobby177 wrote:
but they both push just as hard
Helicopter rotor blades are just wings; they don't work upside down. Both of them have to work against gravity.

If you did this in zero gravity, yes, it would just have them stuck together until one slips. But there is gravity, and they would fall.

If you did this in 0 gravity, then you don't even need the motors to be running for them to stay in one place haha, but assuming that the helicopter rotors are applying the same amount of lifting force, then they will cancel each other out and gravity will cause the whole system to move downwards.

Think about this, in order for you to keep one helicopter which is upright to hover, you will need to provide lift from its rotors, so obviously when you cancel out that lifting force, you'll be getting a mass which is freefalling.

2007-01-03 15:34:08

#21

FesterTheMolester: BF2s US Server Admin, IRC>Forums; +157|6646|The Mind Of A Cereal Killer

they would fall,

seeing as the power of thrust of each would offset eachother, the only force acting on it would be gravity, which pulls you towards the center of the earth

BF2S Forums 2 helicopter question

Superior Mind wrote:

bobby177 wrote:

-=raska=- wrote:

bobby177 wrote:

Superior Mind wrote:

bobby177 wrote:

Skorpy-chan wrote:

bobby177 wrote:

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