Once and for f*cking all....

[wayfast]

Dear all,

As wbarnhill called out, I thought I should step in to what is rapidly becoming a hornet's nest. I will try to calm things down but I don't hold out much hope!

First up, for those concerned that this story has been cancelled, don't worry, planes on a conveyer belt has been filmed, is spectacular, and will be part of what us Mythbusters refer to as 'episode 97'. Currently that is due to air on January 30th.

Secondly, for those very aggrieved fans feeling "duped" into watching tonight's show, I can only apologise. I'm not sure why the listings / internet advertised that tonight's show contained POCB. I will endeavour to find out an answer but for those conspiracy theorists amongst you, I can assure you that it will have just been an honest mistake. At one point
several months ago, POCB was going to be part of Airplane Hour. Somewhere, someone has mistakenly posted the wrong listing. It will have been a genuine mistake but nonetheless it was a mistake which is unacceptable. As said I will try to find out what went wrong and hope that you will see fit to forgive the team at Discovery.

Thanks in advance,

Dan

from disco. site i guess

[Ray Smoodiver]

Oh jesus fucking christ.

The engines don't provide LIFT, they provide THRUST.

If, as the problem states, the belt negates the engines THRUST, therefore with no air over the wings creating LIFT, how, exactly, does the plane take off?

[TwoJ's]

I can't believe there are so many retards around here.

Why the hell are you talking about the friction of the wheels? And what do you even mean by that? Friction between the belt and wheels? Between wheels and bearings? Doesn't matter though, it's irrelevent.

The answer to this problem is simple. It does not depend on friction of anything. It depends on the speed of the plane relative to the ground. That's it. No if's, and's or butt's.

So stop with this nonsense thrust vs. friction talk.

[TwoJ's]

At least i'm not the only person who remembers the earth itself is a giant spinning treadmill that moves faster than an airplane does when it takes off.

Are you kidding me? Is this shit really so hard to understand? When planes take off, they are moving at a certain speed RELATIVE to the surface of the earth.

Before responding to this thread, people should have at least a slight idea of how the world works. Or maybe at least understand the concept of relativity.

Once and for all, this question depends on only one thing: the speed of the plane relative to the earth.

[sleepswithe30s]

Oh jesus fucking christ.

The engines don't provide LIFT, they provide THRUST.

If, as the problem states, the belt negates the engines THRUST, therefore with no air over the wings creating LIFT, how, exactly, does the plane take off?

There is so little that the belt can do to negae the engines thrust, mainly because it pushes through the air, not the belt itself. The Conveyor would have to be spinning inconcievable fast for this to have much effect on how the plane would push itself forward. Also, if the belt is negating the thrust as you have said, I would be willing to make a bet that the plane wouldn't be able to take off from a runway, let alone a conveyorm simply because its not powerful enough.

let me make this simple.

engine push air, air pushed moves plane, Are you still with me?
ok
because plane moves, wheels spin, NOT because engines move wheels spin
are you still there?
Plane is not moving on a runway, engines arent turning
Plane is moving on runway engines are turning. Plane moves fast enough, it takes off.


Now this is what seems to be getting you, You seem to think that the conveyor will be capable of overcoming the thrust that the engines put out, I would just like to say that you are sorely mistaken. The plane just pushes so hard the the friction between the tires, road and bearings in negligable.

Therefor:

Plane on conveyor, conveyor turns, engines turn, but not much, plane is stopped, plane wont take off.

Plane turns on the after burners and pours the gas into the turbines, PUSHES LOTS OF AIR, moves forward, and takes off.

get it? I sure hope so, cause If you dont, I truly feel sorry for all the teachers to have taught you in the past, and you're parents too.

[TwoJ's]

All you people who say its not possible are completely retarded.

Sorry.

But why the hell was this thread ever even considered to be posted? I guess it does help to weed out the morons.

The plane is going forward at x speed, the belt is going back at x speed. wheels are travelling at 2x. thrust from an airplane does NOT come from the wheels. It just means the wheels will be spinning twice as fast as the plane is going at the SURROUNDING ground speed. More friction, sure, but not enough to make a difference.

I'm sorry guy, but you're wrong once again. Your argument is false. You say the plane will be moving forward at speed x. You say the "thrust" does not come from the wheels, so how does it attain this speed x? Oh, that's right it's from the thrust of engines. This thrust moves teh plane forward and the conveyor belt matches the speed but in teh opposite direction. Therefore the speed of the plane relative to the ground is zero and the god damn plane stays on teh ground.

Simple matter of fact is that all of you people don't understand simple classical physics. It's quite funny really.

[sleepswithe30s]

Once and for all, this question depends on only one thing: the speed of the plane relative to the earth.

you're fucking stupid

Its the planes speed relative to the air. Not the ground. and no, the air doesnt move the same speed as the ground
theres such a thing as wind you know.

[golde30]

plane on treadmill video
http://www.youtube.com/watch?v=-EopVDgSPAk

this is proof enough. the wheel speed doesnt equate for shit. watch that damn video and you ppl will all see the plane WILL TAKE OFF!!!!!

[sleepswithe30s]

You say the "thrust" does not come from the wheels, so how does it attain this speed x?

ahahahaha, I hope that wasnt a serious qeustion, no power is provided to the wheels at all on a plane, ever, It moves by pushing the air around it.

[Sean]

The wheels on a plane are like the rear wheels on a FWD car...they just turn. No power is applied to them.

That's all I'm going to offer. KTHXBYE

[TwoJ's]

I want to get in on the betting pool. We can each PayPal an amount to an unbiased 3rd party and the winner will get both PayPal amounts back with 10% going to the holder for his or her efforts.

The plane will fly.

If someone would like to take me up on it, name an amount and we'll take it from there. I would even be willing to bet one of the cars in my .sig on it, but I dunno if I could actually take someone's car regardless of how much physics they understand.

Let me know, I'm serious. :up:

Tim

What are the conditions of the experiment? Lay out the details of the problem and I'll tell if you're right or not, and then I'll bet you.

For example: If the plane is on the belt and the belt is has an equal speed and opposite direction (plane is not moving relative to the ground), the plane will not take off. Want to bet on that?

[TwoJ's]

ahahahaha, I hope that wasnt a serious qeustion, no power is provided to the wheels at all on a plane, ever, It moves by pushing the air around it.

That's exactly my point dumb shit. You seriously amaze me with your stupidity. You said that the plane was moving with speed x AND THEN the thrust moves it forward more. How did the plane achieve this speed x before thrust?

[mspiegle]

ahahahaha, I hope that wasnt a serious qeustion, no power is provided to the wheels at all on a plane, ever, It moves by pushing the air around it.

And don't planes need to be pulled by a vehicle in order to go backwards? Further proof that there's nothing connected to the wheels.

[sleepswithe30s]

And don't planes need to be pulled by a vehicle in order to go backwards? Further proof that there's nothing connected to the wheels.

Im fairly sure they have reverse thrusters (not 100% sure, just guessing by the noise the engines make when they land.

[sleepswithe30s]

That's exactly my point dumb shit. You seriously amaze me with your stupidity. You said that the plane was moving with speed x AND THEN the thrust moves it forward more. How did the plane achieve this speed x before thrust?

x is a variable, meaning it could be anything, including zero.

edit, im not saying that the thrusters suddenly come on increasing the speed, I'm saying the pilot hammers the gas increasing the speed.