Brain Teaser - Will it take off??
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From: North of Dallas, South of Frisco
Originally Posted by rutherk1
Are you not reading this discussion? Its quite obvious that the plane will fly. The wheels dont get the plane moving. The propeller gets it moving by pulling it through the static air. The speed of the wheels is irrelavent.
In a vaccum (Assuming the plane could operate in a vaccum, ie-rocket powered), your suggestion that the wheels are irrelevant is correct. Eventually, the thrust would be so great that the plane could move forward- in a vaccum.
But, since it requires wheels (Since wheels are mentioned in the initial post) for the plane to turn it's thrust or pull into forward momentum, the fact of wheel being turned in a direction opposite of the direction that the plane is trying to move, shoudl theoretically prevent it from taking off into the air. The forward momentum helps creates wind over & under the wings, which results in lift and the plane flying.
If the plane cannot move- I don't give a damm how much you rev the engine, it will not move forward, will not gain speed, will not create lift and will not fly.
Yes, the wheels are powerless, but they are required- unless the plane is on ski's or skids- This was not stated.
Again, this is just a guess. I'm not an aeronautical engineer... But, based upon what I do know about planes, we don't have enough information to make a sound guess, so we have no choice but to use deductive reasoning and go with whatever is left...
Wookie- we don't have to wait 25 pages for the answer- do we?
Last edited by Bighersh; Dec 1, 2005 at 02:02 PM. Reason: To change "this" into "The forward momentum"
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From: Pikesville, MD
Originally Posted by Bighersh
Wookie- we don't have to wait 25 pages for the answer- do we?
The answer according to the engineers is....
Yes the plane will fly....
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From: SW MO
Originally Posted by Bighersh
yes, I have read it- and you guys are thinking about this as if the wheels have nothing to do with the plane taking off- and you are wrong...
In a vaccum (Assuming the plane could operate in a vaccum, ie-rocket powered), your suggestion that the wheels are irrelevant is correct. Eventually, the thrust would be so great that the plane could move forward- in a vaccum.
But, since it requires wheels (Since wheels are mentioned in the initial post) for the plane to turn it's thrust or pull into forward momentum, the fact of wheel being turned in a direction opposite of the direction that the plane is trying to move, shoudl theoretically prevent it from taking off into the air. This creates wind over & under the wings, which results in lift and the plane flying.
If the plane cannot move- I don't give a damm how much you rev the engine, it will not move forward, will not gain speed, will not create lift and will not fly.
Yes, the wheels are powerless, but they are required- unless the plane is on ski's or skids- This was not stated.
Again, this is just a guess. I'm not an aeronautical engineer... But, based upon what I do know about planes, we don't have enough information to make a sound guess, so we have no choice but to use deductive reasoning and go with whatever is left...
Wookie- we don't have to wait 25 pages for the answer- do we?
In a vaccum (Assuming the plane could operate in a vaccum, ie-rocket powered), your suggestion that the wheels are irrelevant is correct. Eventually, the thrust would be so great that the plane could move forward- in a vaccum.
But, since it requires wheels (Since wheels are mentioned in the initial post) for the plane to turn it's thrust or pull into forward momentum, the fact of wheel being turned in a direction opposite of the direction that the plane is trying to move, shoudl theoretically prevent it from taking off into the air. This creates wind over & under the wings, which results in lift and the plane flying.
If the plane cannot move- I don't give a damm how much you rev the engine, it will not move forward, will not gain speed, will not create lift and will not fly.
Yes, the wheels are powerless, but they are required- unless the plane is on ski's or skids- This was not stated.
Again, this is just a guess. I'm not an aeronautical engineer... But, based upon what I do know about planes, we don't have enough information to make a sound guess, so we have no choice but to use deductive reasoning and go with whatever is left...
Wookie- we don't have to wait 25 pages for the answer- do we?
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Originally Posted by Bighersh
yes, I have read it- and you guys are thinking about this as if the wheels have nothing to do with the plane taking off- and you are wrong...
In a vaccum (Assuming the plane could operate in a vaccum, ie-rocket powered), your suggestion that the wheels are irrelevant is correct. Eventually, the thrust would be so great that the plane could move forward- in a vaccum.
But, since it requires wheels (Since wheels are mentioned in the initial post) for the plane to turn it's thrust or pull into forward momentum, the fact of wheel being turned in a direction opposite of the direction that the plane is trying to move, shoudl theoretically prevent it from taking off into the air. This creates wind over & under the wings, which results in lift and the plane flying.
If the plane cannot move- I don't give a damm how much you rev the engine, it will not move forward, will not gain speed, will not create lift and will not fly.
Yes, the wheels are powerless, but they are required- unless the plane is on ski's or skids- This was not stated.
Again, this is just a guess. I'm not an aeronautical engineer... But, based upon what I do know about planes, we don't have enough information to make a sound guess, so we have no choice but to use deductive reasoning and go with whatever is left...
Wookie- we don't have to wait 25 pages for the answer- do we?
In a vaccum (Assuming the plane could operate in a vaccum, ie-rocket powered), your suggestion that the wheels are irrelevant is correct. Eventually, the thrust would be so great that the plane could move forward- in a vaccum.
But, since it requires wheels (Since wheels are mentioned in the initial post) for the plane to turn it's thrust or pull into forward momentum, the fact of wheel being turned in a direction opposite of the direction that the plane is trying to move, shoudl theoretically prevent it from taking off into the air. This creates wind over & under the wings, which results in lift and the plane flying.
If the plane cannot move- I don't give a damm how much you rev the engine, it will not move forward, will not gain speed, will not create lift and will not fly.
Yes, the wheels are powerless, but they are required- unless the plane is on ski's or skids- This was not stated.
Again, this is just a guess. I'm not an aeronautical engineer... But, based upon what I do know about planes, we don't have enough information to make a sound guess, so we have no choice but to use deductive reasoning and go with whatever is left...
Wookie- we don't have to wait 25 pages for the answer- do we?
Sorry.
If you hung the plane from a dome and the plane had no wheels, the prop would still pull it forward.
The wheels are they to reduce the friction between the plane and the ground.
There is also no thrust nor lift in a vacuum so that isnt even a good arguement.
Last edited by rutherk1; Dec 1, 2005 at 02:05 PM.
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From: North of Dallas, South of Frisco
Originally Posted by rutherk1
Yes. That is a guess and is incorrect.
Sorry.
If you hung the plane from a dome and the plane had not wheels, the prop would still pull it forward.
The wheels are they to reduce the friction between the plane and the ground.
Sorry.
If you hung the plane from a dome and the plane had not wheels, the prop would still pull it forward.
The wheels are they to reduce the friction between the plane and the ground.
Originally Posted by closer9
There could be no thrust in a vacuum. The thrust (assumptions again) here is created by a propellor moving air, which doesn't exist in a vacuum...
Last edited by Bighersh; Dec 1, 2005 at 02:08 PM.
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From: Olympia, WA
You are soooo close Hersh, it hurts. The wheels can spin a billion miles an hour if the bearings are slippery enough and the plane will still move forward as though the conveyor was sitting still. The thrust created by the plane is relative to the air - it shoves itself forward thru the air by cramming a bunch of air behind it - the wheels are just a bearing between it and the ground.
You mentioned skis or skids - no, they're not in the equation but they might as well be. wheels, skis, skids, pontoons, whatever, are all just bearings to allow the plane to move accross the ground or water propelled by its ENGINES. If the wheels made a difference in the equation, how would a ski plane ever take off?
Sufficient thrust created by the engines overcomes friction at the wheel/ski/pontoon level and the plane takes off.
Now, if the airframe was actually CHAINED to something stationary, all the thrust in the world isn't going to create any airspeed until the chain breaks.
You mentioned skis or skids - no, they're not in the equation but they might as well be. wheels, skis, skids, pontoons, whatever, are all just bearings to allow the plane to move accross the ground or water propelled by its ENGINES. If the wheels made a difference in the equation, how would a ski plane ever take off?
Sufficient thrust created by the engines overcomes friction at the wheel/ski/pontoon level and the plane takes off.
Now, if the airframe was actually CHAINED to something stationary, all the thrust in the world isn't going to create any airspeed until the chain breaks.
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From: Olympia, WA
Originally Posted by rutherk1
There is also no thrust nor lift in a vacuum so that isnt even a good arguement.
That's why rifles have recoil. Accellerating that piece of lead and spitting all that hot gas out of the barrel creates thrust against your shoulder. Thrust would exist regardles off being in a vacuum.
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Originally Posted by Fritz_H
No lift, but plenty of thrust if you're using a rocket. Or chucking bricks out the back of your truck - all you have to do is shove something away from yourself to create thrust.
That's why rifles have recoil. Accellerating that piece of lead and spitting all that hot gas out of the barrel creates thrust against your shoulder. Thrust would exist regardles off being in a vacuum.
That's why rifles have recoil. Accellerating that piece of lead and spitting all that hot gas out of the barrel creates thrust against your shoulder. Thrust would exist regardles off being in a vacuum.
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From: Friendswood Texas
couple of thig that i thought of to compare.
a person running on a treadmill goes no where. is this not the same thing. one power matching the other canceling each other out. basiacally you are putting the plain on a tredmill that has the ability to match speed. will a kite fly with no wind?and will a plane fly with no wings? flight requires power and lift
a rocket is propelled by shear force, a plain relies on wings and lift.
plane does not fly unless this is a riddel and a key part is not being told.
the engines or jets provide forward thrust, wings provide the lift assuming it is sitting on the run way what power or force would lift the plane since there is not enough air moving over the wings?
a person running on a treadmill goes no where. is this not the same thing. one power matching the other canceling each other out. basiacally you are putting the plain on a tredmill that has the ability to match speed. will a kite fly with no wind?and will a plane fly with no wings? flight requires power and lift
a rocket is propelled by shear force, a plain relies on wings and lift.
plane does not fly unless this is a riddel and a key part is not being told.
the engines or jets provide forward thrust, wings provide the lift assuming it is sitting on the run way what power or force would lift the plane since there is not enough air moving over the wings?
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From: North of Dallas, South of Frisco
Yeah- I read that other web page...
It seems I made the mistake many others made. Assuming (Which I could swear the thread initially said) the conveyer would keep the plane stationary..
The author left a little more to be desired, so I don't know if the experiment he did is indicative of the statement that started all of this. But, I guess I'll reluctantly agree that this is somehow possible...
I just don't see how...
It seems I made the mistake many others made. Assuming (Which I could swear the thread initially said) the conveyer would keep the plane stationary..
The author left a little more to be desired, so I don't know if the experiment he did is indicative of the statement that started all of this. But, I guess I'll reluctantly agree that this is somehow possible...
I just don't see how...
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From: San Antonio Tx
Originally Posted by BROTHERDAVE
couple of thig that i thought of to compare.
a person running on a treadmill goes no where. is this not the same thing. one power matching the other canceling each other out. basiacally you are putting the plain on a tredmill that has the ability to match speed. will a kite fly with no wind?and will a plane fly with no wings? flight requires power and lift
a rocket is propelled by shear force, a plain relies on wings and lift.
plane does not fly unless this is a riddel and a key part is not being told.
the engines or jets provide forward thrust, wings provide the lift assuming it is sitting on the run way what power or force would lift the plane since there is not enough air moving over the wings?
a person running on a treadmill goes no where. is this not the same thing. one power matching the other canceling each other out. basiacally you are putting the plain on a tredmill that has the ability to match speed. will a kite fly with no wind?and will a plane fly with no wings? flight requires power and lift
a rocket is propelled by shear force, a plain relies on wings and lift.
plane does not fly unless this is a riddel and a key part is not being told.
the engines or jets provide forward thrust, wings provide the lift assuming it is sitting on the run way what power or force would lift the plane since there is not enough air moving over the wings?
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From: Friendswood Texas
are you saying i am smart and stupid at the same time 
you know how us Texas boys are, women and money are the priorities and spelling is a ways down the list, (thats what spell checker and assistants are for) l
i think fritz nailed it
you know how us Texas boys are, women and money are the priorities and spelling is a ways down the list, (thats what spell checker and assistants are for) l
i think fritz nailed it
Last edited by BROTHERDAVE; Dec 1, 2005 at 04:47 PM.
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Hersh - you are stuck where I was. The airplane will NOT be stationary on the conveyor belt.
Try to imagine this: A long conveyor belt right beside a sidewalk. You have a little red wagon...you place it on the conveyor belt. You start pulling it along, you walking right beside it on the sidewalk. You walk at 3 mph. So you are pulling the wagon along at 3 mph. The conveyor is off. So the wagon is just rolling along on the non-moving conveyor at 3 mph.
Now, someone turns on the conveyor. They pump up the speed of the conveyor. But, you are still walking at 3 mph, pulling the wagon behind you and just off to your right, on the conveyor. (You are walking along the sidewalk). The little wheels are going the equivalent of 20 mp, because they are reacting to the conveyor. But how fast is the wagon really moving along? (How fast are you, the propeller, making it go?)
You see? It doesn't matter what the wheels and conveyer are doing....the wagon moves because you are pulling it along. If the wagon had wheels that were driven, like a car does, it would be a different story.
So the plane will move forward relative to the runway, because the prop is thrusting it forward, not the wheels. The wheels are just rolling along.
Try to imagine this: A long conveyor belt right beside a sidewalk. You have a little red wagon...you place it on the conveyor belt. You start pulling it along, you walking right beside it on the sidewalk. You walk at 3 mph. So you are pulling the wagon along at 3 mph. The conveyor is off. So the wagon is just rolling along on the non-moving conveyor at 3 mph.
Now, someone turns on the conveyor. They pump up the speed of the conveyor. But, you are still walking at 3 mph, pulling the wagon behind you and just off to your right, on the conveyor. (You are walking along the sidewalk). The little wheels are going the equivalent of 20 mp, because they are reacting to the conveyor. But how fast is the wagon really moving along? (How fast are you, the propeller, making it go?)
You see? It doesn't matter what the wheels and conveyer are doing....the wagon moves because you are pulling it along. If the wagon had wheels that were driven, like a car does, it would be a different story.
So the plane will move forward relative to the runway, because the prop is thrusting it forward, not the wheels. The wheels are just rolling along.