Originally by: Pwett

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You sir, underestimate the things I have and will pee on.

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Originally by: Death4free

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the answer is yes because its a harrier jump jet...

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Originally by: Moneeh

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Using my advanced physics skills () I'd say that the plane's speed will be annihilated by the opposite direction of the conveyor belt. So from a 3rd person perspective it would appear that the plane stands still.

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Originally by: Reven Cordelle

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Since a plane is not powered through its wheels, the plane will still take off.

Consider the fact a plane will move itself by "grabbing" the air in front of it. the air is there, it is not moving with the conveyor.

The plane will therefore merely take off as per usual, its landing gear will be moving in the direction of the conveyor, but since the landing gear has no drive and is merely freewheeling, it'll provide no problem for the plane to travel along the conveyor regardless of how fast the conveyor is moving. Since the wheels can move as fast as they can, the plane is free to take off at its own will.

Pretty simple, barely requires debate.

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Originally by: Kyrall

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it absolutely depends on very careful interpretation of the exact meaning of the question.
The question is usually pretty short, so there are many different things not covered by it, so you can examine loads of different situations depending on the many variables. For example: there are a few ways you can handle things like friction, and whether the conveyor belt is always at exactly the same speed as the aircraft (or its wheels) or if it is just trying to keep up (so there is a slight delay).

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Originally by: Kaeten

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it WON'T take off due to the fact that it's the wings that lift the plane, and as the wings are basiccly stadning still how could they lift the plane, it needs air passing around the wings for it to generate lift.

What stupid idiots thought of that.

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YES

Originally by: Kaeten

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it WON'T take off due to the fact that it's the wings that lift the plane, and as the wings are basiccly stadning still how could they lift the plane, it needs air passing around the wings for it to generate lift.

What stupid idiots thought of that.

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Originally by: Voltain

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Air needs to pass over a wing at the correct velocity and angle to create lift.

If you run on a treadmill in a gym itÆs not bloody windy is it.

A plane running flat out on a treadmill is not moving through the air, its position is static, there is no airflow, engines will not magically create this, and if they did we wouldn't need runways.

What this theory needs is a MASSIVE FAN, the airflow over the wings will create lift, the thrust from the engines will propel the plane into said MASSIVE FAN where it will be chopped to bits and a fireball will erupt when the blades smash into the fuel tanks.

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Originally by: Voltain

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Air needs to pass over a wing at the correct velocity and angle to create lift.

If you run on a treadmill in a gym itÆs not bloody windy is it.

A plane running flat out on a treadmill is not moving through the air, its position is static, there is no airflow, engines will not magically create this, and if they did we wouldn't need runways.

What this theory needs is a MASSIVE FAN, the airflow over the wings will create lift, the thrust from the engines will propel the plane into said MASSIVE FAN where it will be chopped to bits and a fireball will erupt when the blades smash into the fuel tanks.

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Originally by: KaiTech

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The plane would only take of if the airspeed around it's wings would be high enough, it's got nothing to do with the groundspeed.

for instance why do U think airplanes lift off faster if they take off in opposite direction of the wind direction (face the wind)
The only thing that is relevat to flying is the speed of the air, another example, ...:
ever observed an Eagle float above U and it looks as it was standing on 1 place in the air ? ... well that's only possible if it can face the wind and if the wind is blowing fast enough for it to be able to support the weight of the Eagle. Would the wind stop blowing a t the minimal speed it would fall like a rock or it would have to flap it's wings.

So the answer in the case that if U'r conveyor belt isn't producing a sufficient airstream to make the plane lift off it's gonna stay on the ground.

So basically the short answer is : no!


cya in game soon

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Originally by: Voltain

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If you run on a treadmill in a gym it’s not bloody windy is it.

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Quote:

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A plane running flat out on a treadmill is not moving through the air, its position is static

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Originally by: Akita T

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Seriously, I had to see this to believe it... some people REALLY ARE that dense, are they not ?
And apparently, they also post before reading the bolded parts of the OP carefully, let alone parse the entire thread.

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Originally by: Akita T

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I'm curious what the rationale any of you can provide for the WRONG answer.

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Originally by: CCP Greyscale

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My initial reaction was "no, if it's stationary there's obviously no way it'll get lift"...

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Originally by: Reven Cordelle

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Originally by: CCP Greyscale

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My initial reaction was "no, if it's stationary there's obviously no way it'll get lift"...

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I'm glad you saw the light.

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Originally by: Int3r

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Hah i still disagree :)

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Originally by: Reven Cordelle

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Originally by: Kaeten

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it WON'T take off due to the fact that it's the wings that lift the plane, and as the wings are basiccly stadning still how could they lift the plane, it needs air passing around the wings for it to generate lift.

What stupid idiots thought of that.

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So the planes wings are now connected to the ground? The wings are a device of lift, not propulsion.

Plane landing gear is freewheeling, the prop/turbine moves the plane. If the AIRSPEED was moving at the same rate as required for the plane to take off, THEN the plane would essentially FLY on the spot providing it could get up to the local airspeed before crashing.

Ground speed is not even a factor for a plane taking off. The wheels can spin as fast as the conveyor, essentially negating any effect of the conveyor in the first place.

Unless you factor in material thresholds, friction and operational boundaries of the wheels, bearings and axles of the planes landing gear. In that instance the conveyor would have to be moving incredibly fast and merely poses the debate of variables.

Since that view is moot to the original debate;

The plane will take off.

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Originally by: midge Mo'yb

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Originally by: Reven Cordelle

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Originally by: CCP Greyscale

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My initial reaction was "no, if it's stationary there's obviously no way it'll get lift"...

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I'm glad you saw the light.

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the only difference is say the plane takes off at 150 airspeed the wheels will be moving at 300(if they can handle it without blowing up :P)

they wheels are merely there to keep the plane from scraping th rground till it gains enoug hairspeed to generate the lift required to take off

and yes 150 is just me making up numbers, the wheels have no bearing on the planes air speed they will simply move as fast as requires/able

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Originally by: Suze'Rain

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the fact of the matter is, it'll not take off.
look closely.



those wings will never clear the hand-rails going up, so it's never going to take off, because it'll crash horribly into them in a tangled wreck of burning metal and aviation fuel.

wait, am I taking this too literally? :)

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Originally by: Kaeten

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Originally by: Reven Cordelle

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Originally by: Kaeten

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it WON'T take off due to the fact that it's the wings that lift the plane, and as the wings are basiccly stadning still how could they lift the plane, it needs air passing around the wings for it to generate lift.

What stupid idiots thought of that.

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So the planes wings are now connected to the ground? The wings are a device of lift, not propulsion.

Plane landing gear is freewheeling, the prop/turbine moves the plane. If the AIRSPEED was moving at the same rate as required for the plane to take off, THEN the plane would essentially FLY on the spot providing it could get up to the local airspeed before crashing.

Ground speed is not even a factor for a plane taking off. The wheels can spin as fast as the conveyor, essentially negating any effect of the conveyor in the first place.

Unless you factor in material thresholds, friction and operational boundaries of the wheels, bearings and axles of the planes landing gear. In that instance the conveyor would have to be moving incredibly fast and merely poses the debate of variables.

Since that view is moot to the original debate;

The plane will take off.

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I don' know how your wings work but mine work soemthing like here. i don't care about the wheels, they have nothing to do with it tbh, unless the propulsion device is feeding airspeed to the wings it won't lift cause it would be like it was standing still.

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Originally by: Reven Cordelle

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Originally by: Kaeten

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Originally by: Reven Cordelle

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Originally by: Kaeten

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it WON'T take off due to the fact that it's the wings that lift the plane, and as the wings are basiccly stadning still how could they lift the plane, it needs air passing around the wings for it to generate lift.

What stupid idiots thought of that.

---

So the planes wings are now connected to the ground? The wings are a device of lift, not propulsion.

Plane landing gear is freewheeling, the prop/turbine moves the plane. If the AIRSPEED was moving at the same rate as required for the plane to take off, THEN the plane would essentially FLY on the spot providing it could get up to the local airspeed before crashing.

Ground speed is not even a factor for a plane taking off. The wheels can spin as fast as the conveyor, essentially negating any effect of the conveyor in the first place.

Unless you factor in material thresholds, friction and operational boundaries of the wheels, bearings and axles of the planes landing gear. In that instance the conveyor would have to be moving incredibly fast and merely poses the debate of variables.

Since that view is moot to the original debate;

The plane will take off.

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I don' know how your wings work but mine work soemthing like here. i don't care about the wheels, they have nothing to do with it tbh, unless the propulsion device is feeding airspeed to the wings it won't lift cause it would be like it was standing still.

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Good lord.

In the instance of a prop plane, the engine will pull the plane forward creating lift across the wings. The operation of the propellor will create the propulsion to move the plane through the air, which in turn creates lift over the wings. The wheels do not drive the plane.

The wheels will move faster than usual, however they will only act as a support for the plane which is being propelled by its propellor...

Grow a brain, jeez.

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Originally by: Int3r

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Edited by: Int3r on 09/09/2008 14:30:35
The belt can never match the speed of the plane, because the plane gets its speed from pushing back the air around it.

So the plane will move (fly) off the belt, because the belt can never match the speed of the wheels + the plane.

The whole belt matching the wheels speed is just screwing with your mind :)

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Originally by: Kaeten

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[yes the the propeller DOES pull the plane forward however resulting at the speed of ZERO thanks to the fact theres a convayer belt and wheels...

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Originally by: Kaeten

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Originally by: Reven Cordelle

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Originally by: Kaeten

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Originally by: Reven Cordelle

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Originally by: Kaeten

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it WON'T take off due to the fact that it's the wings that lift the plane, and as the wings are basiccly stadning still how could they lift the plane, it needs air passing around the wings for it to generate lift.

What stupid idiots thought of that.

---

So the planes wings are now connected to the ground? The wings are a device of lift, not propulsion.

Plane landing gear is freewheeling, the prop/turbine moves the plane. If the AIRSPEED was moving at the same rate as required for the plane to take off, THEN the plane would essentially FLY on the spot providing it could get up to the local airspeed before crashing.

Ground speed is not even a factor for a plane taking off. The wheels can spin as fast as the conveyor, essentially negating any effect of the conveyor in the first place.

Unless you factor in material thresholds, friction and operational boundaries of the wheels, bearings and axles of the planes landing gear. In that instance the conveyor would have to be moving incredibly fast and merely poses the debate of variables.

Since that view is moot to the original debate;

The plane will take off.

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I don' know how your wings work but mine work soemthing like here. i don't care about the wheels, they have nothing to do with it tbh, unless the propulsion device is feeding airspeed to the wings it won't lift cause it would be like it was standing still.

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Good lord.

In the instance of a prop plane, the engine will pull the plane forward creating lift across the wings. The operation of the propellor will create the propulsion to move the plane through the air, which in turn creates lift over the wings. The wheels do not drive the plane.

The wheels will move faster than usual, however they will only act as a support for the plane which is being propelled by its propellor...

Grow a brain, jeez.

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yes the the propeller DOES pull the plane forward however resulting at the speed of ZERO thanks to the fact theres a convayer belt and wheels...

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Originally by: Vabjekf

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With perfectly frictionless wheels the plane could be sitting there with its engines OFF and the conveyor belt would not move it backwards, it would just sit there, wheels turning backwards.

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Originally by: clone 1

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Originally by: Kaeten

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[yes the the propeller DOES pull the plane forward however resulting at the speed of ZERO thanks to the fact theres a convayer belt and wheels...

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The conveyor belt does not move the air...

If a car sits on treadmill with the belt going backwards at the same rate as the wheels propel the car forward, the car stays stationary, as all forward movement is generated by the wheels and is thus cancelled out by the motion of the belt.

How does a plane move forward :)

http://www.airplaneonatreadmill.com/

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Originally by: Kaeten

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yes the the propeller DOES pull the plane forward however resulting at the speed of ZERO thanks to the fact theres a convayer belt and wheels...

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Originally by: Pwett

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You sir, underestimate the things I have and will pee on.

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Originally by: Kyrall

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Edited by: Kyrall on 09/09/2008 14:51:04
Kaeten, you are arguing a different question to the one given. The OP states that the conveyor belt moves backwards at the same speed as the plane moves forwards. Unfortunately, due to free-spinning wheels, this isn't fast enough to keep the plane stationary.

If the conveyor was set to move backwards at whatever speed it took to hold the plane still (note: really fast) then yes, it would stop the plane taking off.

IMO this would be a much more interesting situation, the OP's wording of the question is a particularly boring one with little room for opinions or variations

Update: clarity.

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Originally by: Kyrall

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Edited by: Kyrall on 09/09/2008 14:51:04
Kaeten, you are arguing a different question to the one given. The OP states that the conveyor belt moves backwards at the same speed as the plane moves forwards. Unfortunately, due to free-spinning wheels, this isn't fast enough to keep the plane stationary.

If the conveyor was set to move backwards at whatever speed it took to hold the plane still (note: really fast) then yes, it would stop the plane taking off.

IMO this would be a much more interesting situation, the OP's wording of the question is a particularly boring one with little room for opinions or variations

Update: clarity.

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Originally by: Akita T

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Seriously, I never heard of it before today (although it's supposedly quite a heated "internet argument"), and it was just an obscure reference in the latest XKCD "footnote" (but the discussion thread in the forums was quite... ahem... lively).
Still, I almost couldn't believe it IS an argument at all in the first place.
I mean, I knew there's plenty of dense people who never paid any attention in basic physics, but to hear that people who CLAIM to be pilots or engineers are arguing about the incorrect answer is just... ungh.


If you are like me and never heard of the thought experiment until today, I'll spare you the google search time and just post it here... I'm curious what the rationale any of you can provide for the WRONG answer.

" An airplane is standing on a (very/sufficiently) long, powerful and fast conveyor belt.
The airplane pilot attempts to take off moving forward.
The controller of the conveyor belt is making the conveyor belt move in the opposite direction with the same speed.
Can the plane take off, yes or no ? "

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Originally by: Kaeten

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this with friction then... the whells friction kinda slows down the speed of the plane. Let's say the plane is going X, and the conveyer belt is going X, the friction of the wheels would cause the plane to be abit slower, resulting in the plan going slighty backwards? But if the plane has the speed X+m)m being whats needed to keep the plane stationary) then it wouldn't be the same speed?

so if the question is that they have the same speed on the dials, why are yuos all talking about if the plane will fly? lol

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Originally by: Vabjekf

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Originally by: Kaeten

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this with friction then... the whells friction kinda slows down the speed of the plane. Let's say the plane is going X, and the conveyer belt is going X, the friction of the wheels would cause the plane to be abit slower, resulting in the plan going slighty backwards? But if the plane has the speed X+m)m being whats needed to keep the plane stationary) then it wouldn't be the same speed?

so if the question is that they have the same speed on the dials, why are yuos all talking about if the plane will fly? lol

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No, its more like, if a plane normaly takes off at '100' and puts enough power to its engines to where it would normally be going forward at 100, the wheel friction from the conveyor under it moving backwards at 100 would cause the plane to actually be moving forward at 90 or so (or maybe closer to 100, i don't know how good aircraft wheels are 0_0).

All the plane would need to do to take off then. Is to put enough power to its engines to normally go 120 or so. The treadmill would go backwards at a speed of 120, but the friction this caused would only drop the plane down to 108 or somthing, and it would still take off.

The ONLY THING THE GROUND CAN DO to the plane, is hold it back with FRICTION, because the plane does not use the ground to propel itself. Wheels entire job is to eliminate friction.

So the plane will be able to take off by putting just a tiny bit more power to the engine (or just using a longer runway in some cases)

The only way the treadmill would be able to stop the plane through friction through the wheels, is if it was going backwards much MUCH faster than the plane was going forward.

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Originally by: Kaeten

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the beginning made sense however this with the plane taking off.

heres my thoughts in a picture

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Originally by: Reven Cordelle

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If planes flew by "blowing air" over their lift surfaces, jet planes would not get off the ground, neither would airliners or microlites."

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Originally by: Kaeten

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Edited by: Kaeten on 09/09/2008 15:33:03

Originally by: Reven Cordelle

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If planes flew by "blowing air" over their lift surfaces, jet planes would not get off the ground, neither would airliners or microlites."

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the thing is that those jetplans ACTULLY MOVE and are not sitting on a convayer belt... so ofc it wouldn't take off

the engine PULLS the whole aircraft forward, as the wings are moving through the air it provides lift.

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Originally by: Reven Cordelle

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gain lift from their local air whilst the engine propels the plane through the air.

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Originally by: P'uck

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HOLY CRAP people! Can you PLEASE get out of the dark middle age?

Abandon all that witchcraft, folks. It's really simple:

As long as airplane wheels can spin freely (and thats how they are built these days, and theres no word about the fictional pilot pulling the fictional wheelbrakes on the fictional plane), it doesnt matter what the conveyor belt does.

The planes propeller/jet engines pulls the plane through the air, which is the medium that matters...

Short version: it takes off just fine. Only chance it doesnt would be;
conveyor belt moves so fast that the ballbearings/tires melt and lock up the wheels.

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Originally by: Bistot Kid

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Yes it will take off because it isn't driven by it's wheels, they are just there to minimise friction between the plane and the ground.

Therefore the thrust from the engines will give it the required air speed, which is what it needs to get lift, and bears no relation to the wheels and the conveyor belt.

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Originally by: Kaeten

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heres my thoughts in a picture

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Originally by: Akita T

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Originally by: Kaeten

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heres my thoughts in a picture

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/facepalm

To simply show you how ridiculous your concept is... how do you explain jets fly ?
The air doesn't get "sucked" over any wings at all by the jet engines.

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Originally by: Kaeten

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Originally by: Reven Cordelle

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gain lift from their local air whilst the engine propels the plane through the air.

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this local air must be moving over the wings for the wings to provide lift yes? question is, if the propeller isn't making this air move through the wings.. what is.

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Originally by: P'uck

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the plane accelerates through the air, thus creating lift on its wings.

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Originally by: P'uck

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that's just a fallacy, think again.

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Originally by: Kaeten

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the jet engine sucks the plane through the air. as the plane moves through the air, the wings pass through the air, and provide lift...

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Originally by: P'uck

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The planes propeller/jet engines pulls the plane through the air, which is the medium that matters...

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Originally by: Voltain

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Originally by: Kaeten

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the jet engine sucks the plane through the air. as the plane moves through the air, the wings pass through the air, and provide lift...

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A Jet engine compresses air it intakes, adds fuel and burns it out the back. The sucking bit of a jet engine can just be seen as fuel (the air part); it provides no thrust, which comes out of the back burny end.

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Originally by: Kaeten

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the jet engine sucks the plane through the air. as the plane moves through the air, the wings pass through the air, and provide lift...

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Quote:

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i think you misunderstood the purpose of that picture, the picture is as if that plane was on a converyer belt as was "stationary".

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Originally by: Kaeten

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can agree with the the plane is being pulled through the air. However where does the air around it's wings get its speed(to mkae the wings lift)?

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Originally by: P'uck

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There's a lot of stuff moving RELATIVE to each other, and that's where all the mysteries are at

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Originally by: Akita T

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If you and me (assumed to be identical in physical stats) are sitting on an icy lake and there's two wooden planks on top of eachother, and I want to move the upper plank in my direction, while you attempt to stop me from doing that by pulling the bottom plank in the opposite direction... can you stop me ?
Or, better still, what exactly do you think it will happen ?

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Originally by: KaiTech

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The plane would only take of if the airspeed around it's wings would be high enough, it's got nothing to do with the groundspeed.

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Originally by: KingsGambit

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This is exactly correct. The ground speed is negated by the conveyer belt and thus the plane is effectively standing still relative to the wind. Therefore it cannot take-off.

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◕◡◕

Originally by: Great Artista

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Doesn't anyone else see it?! We're being trolled by /b/tards!

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Originally by: KingsGambit

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stuff

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Originally by: Ryysa

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Err...
Plane measures airspeed, not speed at the wheels.
Seriously, have you guys even finished school?

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Originally by: Ryysa

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Uh?
Don't know about your country, but in my country you learn in school how a wing works.

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Originally by: Ryysa

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Err...
Plane measures airspeed, not speed at the wheels.
Seriously, have you guys even finished school? And if you have, did you do so much drugs that nothing is left of your brain?

A 12 year old can solve this.

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Originally by: cold lazarus

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Right was not really relying on plane speed to lift the plane but just said that at 100 mph all the bits fit for a healthy take off because I am guessing pretty much that if the plane is lets say standing on a runway and there was a gust of wind that hits the plane it may take off but not in the direction you want it to, so thrust and all sorts of things regulate take off. so the plane is fooled into thinking it had hit 100mph when it has not it can not take off because ALL THE OTHER THINGS THAT REGULATE THE TAKE OFF DONT FIT.
Just a guess though.

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Originally by: Ryysa

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Err...
Plane measures airspeed, not speed at the wheels.
Seriously, have you guys even finished school? And if you have, did you do so much drugs that nothing is left of your brain?

A 12 year old can solve this.

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Originally by: cold lazarus

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I have no doubt the plane will take off eventually

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Originally by: Bei Bao

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I wonder why landing strips are hundreds of meters long and not all neatly 50 meter conveyor belts?
Strip for landing and belt for take off. Would save so much space and noise generated there must be something wrong with the simple example stated by the op me thinks :s

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Originally by: Dheorl

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Originally by: Akita T

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yawn

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I never knew it was possible to stretch your ego THAT much in 1 post

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Originally by: Pria Pus

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So if the belt underneath the plane is negating all movement from the plane - how can it lift off then?

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Originally by: Pria Pus

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Or is the main mistake i make that i still have a jetengine propelled craft in my mind and i need a propeller to maintain 'wind'?

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Originally by: Red Raider

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A happy gamer isnt on the forums, they are playing the game unless they have an idea that they honestly think is helping out.

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Originally by: CCP Greyscale

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My initial reaction was "no, if it's stationary there's obviously no way it'll get lift". Then I did some poking around the interwebs because I figured that if it was that simple there's no way the argument would get off the ground (har har), which in turn led to the "oh, duh, i r dum" moment. Plane speed, even on the ground, is determined by the engine thrust, and the conveyor belt won't make the blindest bit of difference to that. The implicit assumption that the conveyor belt is keeping the plane stationary is complete bunk when you actually think about it - there's no mechanism by which the fact that the ground is moving backwards can have any effect on the acceleration generated by the engines, ignoring tiny amounts of bearing friction.

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Originally by: Red Raider

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A happy gamer isnt on the forums, they are playing the game unless they have an idea that they honestly think is helping out.

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Originally by: Death4free

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the answer is yes because its a harrier jump jet...

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Originally by: Evanade

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It's just that depending on the way the problem is interpreted both answers are correct.

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Originally by: P'uck

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So please, explain how the plane would not take off.

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Originally by: P'uck

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Edited by: P''uck on 10/09/2008 14:05:32
The whole thing is supposed to be an exercise in relativity.
There is some weird wording of the problem that COULD enable you to argue, that the speed of the conveyor ramps up to infinite, making the whole riddle impossible.

Everything the conveyor does is MATCH THE SPEED OF THE PLANE. (it does NOT counter the wheelspin but the movement of the plane relative to the solid ground).

So the conveyor and the wheels are probably spinning at about double liftoff speed, which really isnt THAT fast for most planes, now is it?

edit: also, if you start to argue in THAT direction, youre a tw@t. to quote that cern guy.
because you probably understand the riddle and just try to make it complicated.
or do you really want to have all the friction properties listed when the riddle is told?

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Originally by: Dionisius

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... the plane does not achieve ground speed the regular way, its solely thrust work performed by the engines BUT without the airflow trough the wings that is given when the plane is in a regular airstrip

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Originally by: Dionisius

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FTR i work in an airline ( IT dept ).

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Originally by: P'uck

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Edited by: P''uck on 10/09/2008 14:12:48

Originally by: Dionisius

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... the plane does not achieve ground speed the regular way, its solely thrust work performed by the engines BUT without the airflow trough the wings that is given when the plane is in a regular airstrip

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a) this is wrong.

Originally by: Dionisius

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FTR i work in an airline ( IT dept ).

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b) what has this got to do with anything
are you building aerodynamic laptops?

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Originally by: P'uck

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Edited by: P''uck on 10/09/2008 14:25:45
Apart from the impossibility to build a conveyor that large and smooth it really doesnt matter what kind of plane you put there (unless its a magic plane that accelerates with its wheels).

And I wont explain why its wrong, sorry, it has been covered on the last pages about a hundred times. Short version: It accelerates and creates lift just like a plane on a normal runway. You can, in fact, completely ignore the conveyor. Everything that counts is the speed relative to the AIR. and the effect of the conveyor on the air around the wings is neglectable. If we assume it would do ANYTHING it would probably HELP in taking off, since the air would be moving around in exactly the direction we need it, if we want to create lift.

oh btw:
I cba to explain it any further, if THIS doesnt help, NOTHING will

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Quote:

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EVE is like a sandbox with landmines. Deal with it.

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Originally by: Reven Cordelle

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Simple way of looking at it since people still aren't getting it...

If you put a skateboard on a treadmill and tie a rope to it, set the treadmill to max speed and pull the skateboard towards you even slowly, will the skateboard move toward you?

Yes.

Now replace the skateboard with a plane and the rope with air that the plane uses to gain its thrust and you have your answer. The plane will still move regardless of being on a conveyor, thus it'll still take off.

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Originally by: Howzic

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Christ people (those that believe it won't take off). Maybe a different scenario will work. You're in an ultra-long pool and as you start swimming forward, the bottom of the pool matches your speed the opposite way. Will you move forward? (I'll give you a hint. The answer is yes) The bottom of the pool could move 20X's your speed in the opposite direction and you'd still move forward.

Taking that to the airplane example. The water beneath you is your wheels, your arms are the planes props, pulling through the water or air around you. You move forward.

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Originally by: Dionisius

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A plane is not a skateboard, it needs something to lift it, in this case air, is the air moving trough the wings at enough speed for them to sustain the plain in air?

If yes then the plane takes off.

If not then the plane does not take off.

And thats my question, does the conveyor generate enough airspeed around the plane so that it actually lifts?

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Originally by: Dionisius

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A plane is not a skateboard, it needs something to lift it, in this case air, is the air moving trough the wings at enough speed for them to sustain the plain in air?

If yes then the plane takes off.

If not then the plane does not take off.

And thats my question, does the conveyor generate enough airspeed around the plane so that it actually lifts?

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Originally by: Dionisius

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The aircraft on the conveyor generates no airspeed though its propulsion system manages to keep it stationary on the conveyor and therefore cannot fly.

I've been a pilot for over thirty years and am currently employed by a nationally recognized air carrier.

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Originally by: Dionisius

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Originally by: Reven Cordelle

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Simple way of looking at it since people still aren't getting it...

If you put a skateboard on a treadmill and tie a rope to it, set the treadmill to max speed and pull the skateboard towards you even slowly, will the skateboard move toward you?

Yes.

Now replace the skateboard with a plane and the rope with air that the plane uses to gain its thrust and you have your answer. The plane will still move regardless of being on a conveyor, thus it'll still take off.

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A plane is not a skateboard, it needs something to lift it, in this case air, is the air moving trough the wings at enough speed for them to sustain the plain in air?

If yes then the plane takes off.

If not then the plane does not take off.

And thats my question, does the conveyor generate enough airspeed around the plane so that it actually lifts?

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Originally by: Straight Chillen

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I dont see how moving on a conveyor belt provides a sufficient airstream to reduce enough pressure on the topside of the wing to create lift.

Depending on your frame of refernce, such as an observer to the side, the plane would be stationary. As its not moving foward, it's not moving through the air, and as such its not getting any lift. So no, your plane would stay grounded.

Now if the conveyor belt is moving the air too, thats a different scenario.

Bernoulli's Principal Simplified

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Originally by: Red Raider

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A happy gamer isnt on the forums, they are playing the game unless they have an idea that they honestly think is helping out.

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Originally by: P'uck

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Oh and something else:

This question should be a part of the process you have to go through to get a pilot's license. EVERYWHERE in the world. Just for the sole purpose of us not having to deal with pretend pilots in discussions about the subject.

Well, at least I thought basic knowledge about first grader physics are somewhat required for flying a plane, but hey, maybe I'm wrong.

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Originally by: NanDe YaNen

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Originally by: Straight Chillen

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I dont see how moving on a conveyor belt provides a sufficient airstream to reduce enough pressure on the topside of the wing to create lift.

Depending on your frame of refernce, such as an observer to the side, the plane would be stationary. As its not moving foward, it's not moving through the air, and as such its not getting any lift. So no, your plane would stay grounded.

Now if the conveyor belt is moving the air too, thats a different scenario.

Bernoulli's Principal Simplified

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I will from here forth link to this post every time I want to discredit your input on any subject.

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Originally by: Dionisius

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If the plane has no motion relative to the wind, there will be no lift to force the plane up.

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Originally by: Pwett

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That means that planes flying against the wind will fly faster, right?

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Originally by: Pwett

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hehe, this should clear up the argument

This, I will get, for you.

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Originally by: Dionisius

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Edited by: Dionisius on 10/09/2008 19:48:01
If the plane and ground speed are matched the plane does not move period!
Notice the question dummies

" An airplane is standing on a (very/sufficiently) long, powerful and fast conveyor belt.
The airplane pilot attempts to take off moving forward.
The controller of the conveyor belt is making the conveyor belt move in the opposite direction with the same speed.
Can the plane take off, yes or no ? "

Both speeds are matched! If you have V0 condition you aren't at proper speed to take off look at the freaking picture Akita posted - > PICTURE

And for the genius stating that the engines propel the plane, true, now your assumption is on a normal strip, take the example and you don't have enough attrition for that you have to generate more power in order to move the plane forward, which is not the case.

Second, the belt itself does not generate enough airflow to cause the sustenance needed to lift the plane, which is for a plane to take off.

And p'uk or puke... lol @ you , seriously.


Edit: For more clearance

The plane gets its lift via the Bernoulli effect.

This has to do with wing shape and its interaction with air moving rapidly past.

If the plane has no motion relative to the wind, there will be no lift to force the plane up.


I think thats the clearer my English can be for the moment :P

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Originally by: Sharupak

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Originally by: Dionisius

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Edited by: Dionisius on 10/09/2008 19:48:01
If the plane and ground speed are matched the plane does not move period!
Notice the question dummies

" An airplane is standing on a (very/sufficiently) long, powerful and fast conveyor belt.
The airplane pilot attempts to take off moving forward.
The controller of the conveyor belt is making the conveyor belt move in the opposite direction with the same speed.
Can the plane take off, yes or no ? "

Both speeds are matched! If you have V0 condition you aren't at proper speed to take off look at the freaking picture Akita posted - > PICTURE

And for the genius stating that the engines propel the plane, true, now your assumption is on a normal strip, take the example and you don't have enough attrition for that you have to generate more power in order to move the plane forward, which is not the case.

Second, the belt itself does not generate enough airflow to cause the sustenance needed to lift the plane, which is for a plane to take off.

And p'uk or puke... lol @ you , seriously.


Edit: For more clearance

The plane gets its lift via the Bernoulli effect.

This has to do with wing shape and its interaction with air moving rapidly past.

If the plane has no motion relative to the wind, there will be no lift to force the plane up.


I think thats the clearer my English can be for the moment :P

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Hey Kor anon! I changed my mind! I just figured out who gets culled or ww3d!

Seriously, is this like some sort of brain disease!

PLEASE EXPLAIN HOW TEH COVEYOR COUNTERACTS THE PROPULSION FROM A JET ENGINE OR PROPELLOR!!! "Because it moves backward at the same speed the plane moves foward " Is not a ****ing answer! BECAUSE THE PLANE WHEELS ROLL FREELY THE CONVEYOR HAS NO WAY TO EXERT A FORCE ON THE PLANE TO COUNTERACT THE FORCE OF THE JET PROPULSION!

I am done, this thread is making me yell now!

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Originally by: Dionisius

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Edited by: Dionisius on 10/09/2008 19:48:01
If the plane and ground speed are matched the plane does not move period!
Notice the question dummies

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Quote:

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" An airplane is standing on a (very/sufficiently) long, powerful and fast conveyor belt.
The airplane pilot attempts to take off moving forward.
The controller of the conveyor belt is making the conveyor belt move in the opposite direction with the same speed.
Can the plane take off, yes or no ? "

Both speeds are matched! If you have V0 condition you aren't at proper speed to take off look at the freaking picture Akita posted - > PICTURE

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Originally by: Vabjekf

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Edited by: Vabjekf on 10/09/2008 21:11:21
Edited by: Vabjekf on 10/09/2008 21:10:13

Originally by: Dionisius

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Edited by: Dionisius on 10/09/2008 19:48:01
If the plane and ground speed are matched the plane does not move period!
Notice the question dummies

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Yes, yes it does move.

Quote:

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" An airplane is standing on a (very/sufficiently) long, powerful and fast conveyor belt.
The airplane pilot attempts to take off moving forward.
The controller of the conveyor belt is making the conveyor belt move in the opposite direction with the same speed.
Can the plane take off, yes or no ? "

Both speeds are matched! If you have V0 condition you aren't at proper speed to take off look at the freaking picture Akita posted - > PICTURE

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And if the plane is moving forward at a speed of 10generic measurements per millisecond, the treadmill will be moving backwards at 10generic measurements per millisecond. They will both be moving at 10 generic measurements per millisecond compared to the surrounding scenery (and in opposite directions), but will be moving at 20 generic measurements per millisecond in relation to each other. Because the plane does not care that it is on a treadmill one bit. Only its wheel bearings will get hotter. It will take off like it was on a normal runway.

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Originally by: Dionisius

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If the belts speed and plane are the same in oposite directions how can the plane be moving ffs?

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Originally by: Dionisius

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...

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Originally by: P'uck

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OMG pilot guy in that vid My faith in mankind, its DESECRATED

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Originally by: Archonus

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probably already posted here somewhere but..
http://www.youtube.com/watch?v=0ul_5DtMLhc

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Originally by: Archonus

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probably already posted here somewhere but..
http://www.youtube.com/watch?v=0ul_5DtMLhc

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Originally by: Merin Ryskin

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Ok, time for an actual pilot and aerospace engineering student to come in and give the correct answer.


The most obvious trap here is the assumption the question expects you to make, that a plane's wheels work like car wheels. They don't. Except for a tiny amount of friction between the wheel and axle, a plane's wheels spin freely. The belt simply can not apply force to the airplane, no matter how fast it is moving. The only way the belt can prevent the airplane from taking off is for one of the following to be true:

1) The airplane is barely able to take off (whether due to lack of runway distance, too much load, etc) normally, and the tiny amount of force applied through friction in the wheels is enough to keep it from reaching takeoff speed. The plane runs off the end of the runway and crashes.

2) The airplane's wheels are unable to survive the extra stress of moving twice as fast and fail. The result is much higher friction between the destroyed landing gear and the moving belt, and the belt is able to apply force to the airplane and stop it from moving.

While #2 is definitely a risk and depends on the airplane, it's probably not enough. The Cessna 172 I fly can, with a soft-field takeoff, get the wheels off the ground at around 30-40 knots. And as demonstrated by me (and every other student pilot in the history of flying), the airplane is quite capable of surviving a landing at 60 kts. A brief time with the wheels rotating at the equivalent of 80 kts is unlikely to break anything, so the plane flies away just fine.


If you still disagree, go get a toy car and a treadmill. Turn the treadmill on as fast as you like, but the car on the belt, and push it forward. Notice that you can move it forward as fast as you like, no matter how fast the belt is moving. Come back here and post your concession that I am right.

Anyone who still thinks the plane fails to take off is either a ****ing idiot or a troll. I leave it to you to decide which.

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Originally by: Dionisius

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Anyways the answer remains NO for obvious reasons.

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Originally by: Dionisius

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And stop using the car example, cars do not work has planes.

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Originally by: Crumplecorn

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Originally by: Dionisius

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And stop using the car example, cars do not work has planes.

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That car does, as the 'thrust' is being applied to the body.

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Originally by: Dionisius

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Originally by: Crumplecorn

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Originally by: Dionisius

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And stop using the car example, cars do not work has planes.

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That car does, as the 'thrust' is being applied to the body.

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You realize that the source of movement of the car is the wheels and that the source of movement for the plane is the reactor or propeller and air displacement under and above the wings right?

And weight / speed ( airspeed ) have a crucial importance in a place takeoff, no one is considering this.

Other than that you have the old small planes with propellers and the more modern airliners of private jets that use reactors, all with differing in aerodinamical properties, while the small propeller plane can takeoff due to the fact that it has,

- lightweight
- Propeller is in front of the wings(*)

therefore generating enough airflow through the wings that creates the desired pressures for them to lift the plane.

Taking off in an aircraft isn't solely a speed experience.

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Originally by: Dionisius

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Edited by: Dionisius on 11/09/2008 14:25:01
Edited by: Dionisius on 11/09/2008 14:24:31

Originally by: Crumplecorn

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Originally by: Dionisius

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And stop using the car example, cars do not work has planes.

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That car does, as the 'thrust' is being applied to the body.

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You realize that the source of movement of the car is the wheels and that the source of movement for the plane is the reactor or propeller and air displacement under and above the wings right?

And weight / speed ( airspeed ) have a crucial importance in a place takeoff, no one is considering this.

Other than that you have the old small planes with propellers and the more modern airliners of private jets that use reactors, all with differing in aerodinamical properties, while the small propeller plane can takeoff due to the fact that it has,

- lightweight
- Propeller is in front of the wings(*)

(*) therefore generating enough airflow through the wings that creates the desired pressures for them to lift the plane.

A private jet or a regular airliner wouldn't take off, they don't meet these conditions, if the conveyor always matches the planes speed it will never achieve the enough air mass displacement to lift.

For a better example, take the carrier catapult into consideration, why do the pilots have to be in full throttle and lower fuel than usual?

Weight and airspeed issues, they have to take off in a rather small space and achieve enough airspeed with minimal possible weight in order to the plane to keep going, this wouldn't happen in the said conveyor in a regular craft with both speeds ( conveyor and plane ) matched.

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Originally by: Dionisius

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Edited by: Dionisius on 11/09/2008 14:25:01
Edited by: Dionisius on 11/09/2008 14:24:31

Originally by: Crumplecorn

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Originally by: Dionisius

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And stop using the car example, cars do not work has planes.

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That car does, as the 'thrust' is being applied to the body.

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You realize that the source of movement of the car is the wheels and that the source of movement for the plane is the reactor or propeller and air displacement under and above the wings right?

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Originally by: Dionisius

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And weight / speed ( airspeed ) have a crucial importance in a place takeoff, no one is considering this.

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Originally by: Sharupak

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My wife was saying no because she interpenetrated the question to mean that the question was telling her to imagine that the conveyor belt "DID" prevent the plane from moving forward for the purposes of the imaginary scenario.

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Originally by: Dionisius

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Whatever, believe what you want.

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Originally by: Dionisius

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Originally by: Archonus

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probably already posted here somewhere but..
http://www.youtube.com/watch?v=0ul_5DtMLhc

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That thing wich they called an experience was so badly performed and so far away from the original question that its even an embaracement to science.
Anyways the answer remains NO for obvious reasons.

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Originally by: Sharupak

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but she thought from interpreting the question that you were supposed to imagine that the conveyor was preventing the plane from moving.

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Originally by: P'uck

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Originally by: Sharupak

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but she thought from interpreting the question that you were supposed to imagine that the conveyor was preventing the plane from moving.

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Could it possibly be that you worded the question poorly? That can happen, from time to time

I usually tell it to people somewhat like "The conveyor belt is moving in the opposite direction of the plane, at the same speed."

Put "and tries to counter the movement" in there, and you got an ingredient for a snafu.

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Originally by: Crumplecorn

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Originally by: Sharupak

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My wife was saying no because she interpenetrated the question to mean that the question was telling her to imagine that the conveyor belt "DID" prevent the plane from moving forward for the purposes of the imaginary scenario.

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See also.

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Originally by: Dmian

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For those of you who believe the plane doesn't take off, this image will surely persuade you:
Image

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Originally by: P'uck

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Edited by: P''uck on 11/09/2008 15:38:34
I had a guy in school that couldnt grasp the concept of density. He was arguing that a car, after it has been crunched to a little metal cube at the junkyard, must be lighter than before (and he was not talking about broken glass and fluids and small shit falling out) because it's smaller.

It was really weird to observe, because he was so convinced that he was right, that he couldnt wrap his mind around the fact that he was just wrong. And there was no way of explaining to him why it is that way, much like trying to explain a color to somebody that has been blind since birth.

I have to admit, I have one of those hangups, too: acceleration in free fall (in vacuum if you want, so we can neglect air resistance and therefor the size of the objects). I KNOW if you drop different stuff that has different mass, they will accelerate at the same rate. But I fail to completely understand why.

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Originally by: P'uck

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Edited by: P''uck on 11/09/2008 15:38:34
I had a guy in school that couldnt grasp the concept of density. He was arguing that a car, after it has been crunched to a little metal cube at the junkyard, must be lighter than before (and he was not talking about broken glass and fluids and small shit falling out) because it's smaller.

It was really weird to observe, because he was so convinced that he was right, that he couldnt wrap his mind around the fact that he was just wrong. And there was no way of explaining to him why it is that way, much like trying to explain a color to somebody that has been blind since birth.

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Originally by: Suzerain

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it's fantastic to read. utterly barking mad.

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Originally by: Pwett

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The great thing about this argument, is that it proves, without the shadow of a doubt, that planes without wheels can not fly.

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Originally by: Pwett

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The great thing about this argument, is that it proves, without the shadow of a doubt, that planes without wheels can not fly.

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Originally by: Sharupak

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I think he was being sarcastic...

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Originally by: Suze'Rain

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Originally by: Sharupak

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I think he was being sarcastic...

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so am I :)

mind you.

Video footage of Ekranoplans on land.

scary, stuff :)

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Originally by: Sharupak

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Originally by: Suze'Rain

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Originally by: Sharupak

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I think he was being sarcastic...

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so am I :)

mind you.

Video footage of Ekranoplans on land.

scary, stuff :)

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Nato was very afraid of it when the Soviets first built it.

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| I BELIEVE |
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