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Ok, I'm sure some of you have seen this before, but did you come to the right conclusion? This was posted on another forum I visit and the thread went on for 30 pages and eventually split into 2 other threads, it was hilarious.

The question:

Imagine a plane is sat on the beginning of a massive conveyor belt/travelator type arrangement, as wide and as long as a runway, and intends to take off. The conveyer belt is designed to exactly match the speed of the wheels at any given time, moving in the opposite direction of rotation.


Can the plane take off?

Correct answer gets a pat on the back and a cookie.

Since the plane is standing still id say no because there is no force pushing the wings upwards.

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I gave up after the first page.

But anyway.. i say yes.

Engine / thruster things pushes plane forward.

Wheels move freely, they wont be connected to engine.

So, conveyor belt wont have any affect on the plane.

There's no velocity and pushing force giving the speed needed for lift-off. So I'd say no.

Yes it can take off. Once you over come the friction caused by the conveyor belt and the wheels, it will go forward. And jet engines can easily overcome said friction. The wheels aren't what makes a plane take off.

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I'm really starting to hate the facepalm smily.

It gets used in every thread, way overused.

Mythbusters already proved this, so yes.

no, you need wind resistance/movement around the wings. if the conveyor belt keeps it still it wouldnt be able to move. why the fuck would this turn into a 30 page thread?

Airplanes fly thanks to Bernoulli's effect so when the speed of the plane is high enough, the pressure under the wing is much higher than the pressure above it, causing the plane to lift off. Therefore i say that it will take off regardless if it's moving on its wheels or on a conveyor belt.

Devilman wrote:Airplanes fly thanks to Bernoulli's effect so when the speed of the plane is high enough, the pressure under the wing is much higher than the pressure above it, causing the plane to lift off. Therefor i say that it will take off regardless if it's moving on its wheels or on a conveyor belt.

but it isnt moving... wind has to move under the wings to cause the lift.


*edit*
the arc in the top of the wing forces the air to travel a longer distance. the wind under the wing moves a shorter distance. (maybe its vice versa, im not sure, i havent been in school in a billion years.) this essectially causes lift. there is more too it, but this forum isnt worth the time.

http://science.howstuffworks.com/airplane8.htm <-- go there

CeLL wrote:

Devilman wrote:Airplanes fly thanks to Bernoulli's effect so when the speed of the plane is high enough, the pressure under the wing is much higher than the pressure above it, causing the plane to lift off. Therefor i say that it will take off regardless if it's moving on its wheels or on a conveyor belt.

but it isnt moving... wind has to move under the wings to cause the lift.

The first post states that the conveyor belt is designed to move at the same speed as the wheels of the plane, which in my opinion means that the whole plane should be moving at the speed needed for lift off. On the other hand, i'm a bit confused by this "...match the speed of the wheels at any given time, moving in the opposite direction of rotation." . I'm not sure which way is the opposite direction of rotation

Devilman wrote:

CeLL wrote:

Devilman wrote:Airplanes fly thanks to Bernoulli's effect so when the speed of the plane is high enough, the pressure under the wing is much higher than the pressure above it, causing the plane to lift off. Therefor i say that it will take off regardless if it's moving on its wheels or on a conveyor belt.

but it isnt moving... wind has to move under the wings to cause the lift.

The first post states that the conveyor belt is designed to move at the same speed as the wheels of the plane, which in my opinion means that the whole plane should be moving at the speed needed for lift off. On the other hand, i'm a bit confused by this "...match the speed of the wheels at any given time, moving in the opposite direction of rotation." . I'm not sure which way is the opposite direction of rotation

Imagine running on a treadmill.

Devilman wrote:

CeLL wrote:

Devilman wrote:Airplanes fly thanks to Bernoulli's effect so when the speed of the plane is high enough, the pressure under the wing is much higher than the pressure above it, causing the plane to lift off. Therefor i say that it will take off regardless if it's moving on its wheels or on a conveyor belt.

but it isnt moving... wind has to move under the wings to cause the lift.

The first post states that the conveyor belt is designed to move at the same speed as the wheels of the plane, which in my opinion means that the whole plane should be moving at the speed needed for lift off. On the other hand, i'm a bit confused by this "...match the speed of the wheels at any given time, moving in the opposite direction of rotation." . I'm not sure which way is the opposite direction of rotation

no. it means the plane doesnt move. no wind movement the cancel each other out.wheels are spinning yes, but it isnt the wheel spinning that brings lift, it is the actual wind movement.

Suck it!

http://mythbustersresults.com/episode97

Toasty wrote:

Devilman wrote:

CeLL wrote:but it isnt moving... wind has to move under the wings to cause the lift.

The first post states that the conveyor belt is designed to move at the same speed as the wheels of the plane, which in my opinion means that the whole plane should be moving at the speed needed for lift off. On the other hand, i'm a bit confused by this "...match the speed of the wheels at any given time, moving in the opposite direction of rotation." . I'm not sure which way is the opposite direction of rotation

Imagine running on a treadmill.

Guess I misunderstood. I was thinking that the plane wasn't moving thanks to its engines, but the belt was propelling in it in the direction of takeoff. In that case i think the plane would lift off at least for a short while. But if plane is moving in a "treadmill" fashion, then it won't lift off. I hope u guys understand what i was trying to say here

To clarify, "opposite" direction means the conveyor would turn in the opposite direction of travel. Plane goes right, conveyor goes left.

EvGa wrote:

To clarify, "opposite" direction means the conveyor would turn in the opposite direction of travel. Plane goes right, conveyor goes left.

plane goes forward and conveyor goes back?

Smi!ezZ wrote:Suck it!

http://mythbustersresults.com/episode97

CeLL wrote:no, you need wind resistance/movement around the wings. if the conveyor belt keeps it still it wouldnt be able to move. why the fuck would this turn into a 30 page thread?

Hahaha.

rumpleKillskin wrote:

Smi!ezZ wrote:Suck it!

http://mythbustersresults.com/episode97

CeLL wrote:no, you need wind resistance/movement around the wings. if the conveyor belt keeps it still it wouldnt be able to move. why the fuck would this turn into a 30 page thread?

Hahaha.

there has to be something flawwed in that study, because if this is the case then a plane SHOULD be able to take off from a stand still.

CeLL wrote:

rumpleKillskin wrote:

Smi!ezZ wrote:Suck it!

http://mythbustersresults.com/episode97

CeLL wrote:no, you need wind resistance/movement around the wings. if the conveyor belt keeps it still it wouldnt be able to move. why the fuck would this turn into a 30 page thread?

Hahaha.

there has to be something flawwed in that study, because if this is the case then a plane SHOULD be able to take off from a stand still.

harriers.

but in all seriousness. the wheels are not part of the engine. it is the thrust from the actual engines that is enabling the plane the plane to take off. I know where you are coming from, but there is more to this that I cannot explain in my own words. This is why we have science gurus to explain it to us.

Misc section? :3

CeLL wrote:

rumpleKillskin wrote:

Smi!ezZ wrote:Suck it!

http://mythbustersresults.com/episode97

CeLL wrote:no, you need wind resistance/movement around the wings. if the conveyor belt keeps it still it wouldnt be able to move. why the fuck would this turn into a 30 page thread?

Hahaha.

there has to be something flawwed in that study, because if this is the case then a plane SHOULD be able to take off from a stand still.

sorry CeLL but no... the wheels do not propel the plane like you are thinking. they just prevent friction on the ground. no matter how fast the wheels go, the plane will be propelled forward by the engines. The wheels just make sure the plane doesnt get stuck to the ground, so no mater how fast the belt is going the plane wont be hindered.

So the engines or propeller push the air in a way that allows the plane to rise due to air pressure under the wing being higher? And because this force initially pushes the plane forward you need wheels to cancel out friction caused by the forward movement on the ground.

Sound good or am I off a bit?

why does a plane even need to move down a runway? why not create take off stations then?

CeLL wrote:why does a plane even need to move down a runway? why not create take off stations then?

What they are trying to say is that the plane doesnt stand still.

CeLL wrote:why does a plane even need to move down a runway? why not create take off stations then?

because it needs to gain speed to take off. But the WHEELS do not provide this speed. They only reduce friction so the plane does not get stuck on the ground.

Yes, it will. They did it on Mythbusters.

BloodyBlade wrote:Misc section? :3

wasn't this on mythbusters?

EvGa wrote:

BloodyBlade wrote:Misc section? :3

I knew it!