Would the plane take off?

[tropical_fishy]

My physics is a bit fuzzy (I had a moron for an AP Physics teacher who said things like "we don't call Fred 'Joe'. Thus, we do not call omega 'w'." But that's another story) but I would think that if the airplane isn't moving, then no lift can be generated. The conveyor belt is acting like friction, only friction... that acts in perfect opposition to the movement, rather than a fraction of it. I guess my point is that the engine can provide thrust, but the plane can only move forward as fast as the wheels are moving, and if the ground under the wheels is meant to move in perfect opposition, the plane will go nowhere.

But like I said, my physics are fuzzy.

[Tobe2be]

i would have voted PIE but i guess you forgot to place it in the poll

[PyRo]

For anyone who thinks the plane is going to take off drink some antifreeze, it's yummy.

I don't know how much more basic this can get.
How do planes fly? Lift...

How is lift generated? Air moving over the surfaces of the wings.

Can an object that is stationary relative to the surrounding air have any air passing over its surfaces? No

If their is no air passing over the surface of the wings can a plane have lift? No

Can a normal plane fly without lift? No


Someone disagree with me and get smacked.

[nippinout]

My physics is a bit fuzzy (I had a moron for an AP Physics teacher who said things like "we don't call Fred 'Joe'. Thus, we do not call omega 'w'." But that's another story) but I would think that if the airplane isn't moving, then no lift can be generated. The conveyor belt is acting like friction, only friction... that acts in perfect opposition to the movement, rather than a fraction of it. I guess my point is that the engine can provide thrust, but the plane can only move forward as fast as the wheels are moving, and if the ground under the wheels is meant to move in perfect opposition, the plane will go nowhere.

But like I said, my physics are fuzzy.

Let's do an experiment. Take a sheet of paper. That will be your runway. Now use a toy airplane, or a Matchbox car if you have one. Let's pretend it's a 747 on a runway. That toy will have thrust- so move it along the paper, but the paper will move back at the same speed as the toy is moving forward. No matter how fast or how slow the toy moves, the toy is still able to move forward relative to the ground underneath the paper.

[nippinout]

For anyone who thinks the plane is going to take off drink some antifreeze, it's yummy.

I don't know how much more basic this can get.
How do planes fly? Lift...

How is lift generated? Air moving over the surfaces of the wings.

Can an object that is stationary relative to the surrounding air have any air passing over its surfaces? No

If their is no air passing over the surface of the wings can a plane have lift? No

Can a normal plane fly without lift? No


Someone disagree with me and get smacked.

The plane is moving! Thrust from the engines moves air backwards, to propel the plane forwards. Equal and opposite... M1V1=M2V2

What happens at the wheels is not important! The engines produce forward thrust no matter what is going on with the wheels.

[tropical_fishy]

Let's do an experiment. Take a sheet of paper. That will be your runway. Now use a toy airplane, or a Matchbox car if you have one. Let's pretend it's a 747 on a runway. That toy will have thrust- so move it along the paper, but the paper will move back at the same speed as the toy is moving forward. No matter how fast or how slow the toy moves, the toy is still able to move forward relative to the ground underneath the paper.

There's no way you can move them at the same rate though.

....draw me a diagram, then I'll believe it.. What can I say, I'm a visual person.

[nippinout]

New experiment.

Don't actually do this, you'll hurt yourself.

You need:
Rollerskates, helmet, treadmill, yourself, and a friend.

Strap on the skates and helmet and get on the treadmill. Turn on the treadmill.

You'll remain pretty much stationary. But you have thrust. Have your friend push you. You are moving forward! Your skate wheels and the treadmill don't factor into the speed at which your friend can push you!

The wheels and treadmill are irrelevant! Your friend can push you no matter how fast things are moving.

[PyRo]

The plane is moving! Thrust from the engines moves air backwards, to propel the plane forwards. Equal and opposite... M1V1=M2V2

What happens at the wheels is not important! The engines produce forward thrust no matter what is going on with the wheels.

You sir deserve a smack.

The plane is remaining on one spot on the belt. This means you can stand right next to the belt and the plane will not move an inch relative to you correct? That is the situation he is describing in the question.

How in the hell can their be air moving over the surface of the wings if the plane is not moving relative to the air around it. Stupid people suck

[neppo1345]

For anyone who thinks the plane is going to take off drink some antifreeze, it's yummy.

I don't know how much more basic this can get.
How do planes fly? Lift...

How is lift generated? Air moving over the surfaces of the wings.

Can an object that is stationary relative to the surrounding air have any air passing over its surfaces? No

If their is no air passing over the surface of the wings can a plane have lift? No

Can a normal plane fly without lift? No


Someone disagree with me and get smacked.

Smack me...come on...do it...judging by your response...thats about all you'll be doing for the rest of your life...hope you're a big guy...

What we have here my "friend" are TWO systems...

System 1. The 747's four Prat and Whitney PW4056 Turbofan Engines interacting with the Air

System 2. The 747's 18 tires and the Tarmac

System 2 is virtually frictionless meaning that with a little thrust forward the plane could stand still with the conveyor moving at 1.2 million miles per hour in the opposite direction. Once System 1 overcomes the little friction created by system two the resulting motion will be caused strictly by system 1, will be in a forward direction, and will eventually result in takeoff...

[nippinout]

You sir deserve a smack.

The plane is remaining on one spot on the belt. This means you can stand right next to the belt and the plane will not move an inch relative to you correct? That is the situation he is describing in the question.

How in the hell can their be air moving over the surface of the wings if the plane is not moving relative to the air around it. Stupid people suck

So we're looking at a word problem wrapped in semantic tomfoolery? 'Plane is sitting on a runway' and 'plane moves in one direction, while the conveyor moves in the opposite direction' are both in the question. Looks like a physics problem to me.

[Tobe2be]

if a cat chokes on a dead mouse who killed who?

[Miscue]

You don't have to have lift from an airfoil for flight. Look at a rocket for instance. Thrust alone will get it into the air.

With sufficient thrust, you can get something that looks and works nothing like an airplane to fly around.

But if this airplane is able to take off without lift... is it still an airplane?

I guess it has to do with what you think the requirements are for something to be considered an airplane.

Personally, I think that something that can take off from a standstill is more of a rocket than an airplane. What I consider to be a pure airplane would not be able to take off in this conveyor belt situation.

[nippinout]

You don't have to have lift from an airfoil for flight. Look at a rocket for instance. Thrust alone will get it into the air.

With sufficient thrust, you can get something that looks and works nothing like an airplane to fly around.

But if this airplane is able to take off without lift from the wings... is it still an airplane?

I guess it has to do with what you think the requirements are for something to be considered an airplane.

Personally, I think that something that can take off from a standstill is more of a rocket than an airplane. What I consider to be a pure airplane would not be able to take off in this conveyor belt situation.

Dear god, not you Miscue! Get on that treadmill now!

[UTDragun]

the answer is no, you wanna know why? cuz you didnt specify what kind of conveyor runway, have you seen pearl harbor? they had trouble with a medium bomber, now way a 747 can take off a carrier

as far as I can see, If your thrust > friction of wheels then it shouldnt make a difference whether its on a conveyor or not

[Miscue]

YES...the plane would take off

You people forget the the plane's motion is derived from the interaction of the jet exhaust with the air, and not from the planes landing gear with the tarmac.

If it was a car it would remain stationary, but the plane would have nothing to negate it's thrust and would therefore still accelarate.

Since there is nothing to counteract the thrust of the engines, the plane would still move forward on the conveyor and reach speed to take off.

The wheels would simply spin twice as fast (the groundspeed would be twice the airspeed until it got off the ground) and it might take more thrust to counteract the friction produced in the wheel bearings coeffecient of friction between the pavement...etc etc.

I am not going to school to be an aerospace engineer...I don't know what I'm talking about...
EDIT: Oh wait...I am...and I do...

Pretentiousness... yay! Let us know when you decide that, "It's not what I really wanted to do," and end up enrolling in a liberal arts program.