Plane On A Conveyor Belt

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Will The Plane Fly?

  • Hell Yeah - That Plane WILL Fly!

    Votes: 0 0.0%
  • Um .. No, The Plane WILL NOT FLy.

    Votes: 1 50.0%
  • That Plane is Going To Crash.

    Votes: 1 50.0%
  • Screw The Plane! Bring on the EB.com Art Gallery!!!

    Votes: 0 0.0%

  • Total voters
    2
About This Video
Ok, since some people were confused by the tape to stop it the plane from falling off, I run the plane at a low throttle to match rolling friction w/ thrust. I then accelerate the treadmill to almost 10 MPH w/o changing the throttle position. Then I throttle it up to prove that the plane can move at the high treadmill speed.

The treadmill does not affect the airplane's performance; this shows that no matter what the treadmill does (accelerate the same as the plane, faster than the plane, or less than the plane) the plane will still move forward.

Again, the plane will take off.
 
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Excuse me if I am missing the sarcasm, but are you guys really serious?? A wing produces lift from motion relative to the air, not movement relative to the ground or relative to a treadmill. An airplane on a treadmill will not take off by virtue of the belt rolling under it's wheels.

I am going to assume you are all joking and too much studying has killed my sense of humour. Is this like that guy on the radio who pretends to espouse ridiculous beliefs just so listeners will call up in an outraged tizzy, so as to derive a laugh at the people who were taking it all so seriously?

 
Okay,

I'm really suspecting everyone is PM'ing each other and saying "get on there and tell DVINNY that the plane won't fly, it'll be funny"

^^^ gotta be something like that. You can't be serious that it won't move. Not at this point.

 
Excuse me if I am missing the sarcasm, but are you guys really serious?? A wing produces lift from motion relative to the air, not movement relative to the ground or relative to a treadmill. An airplane on a treadmill will not take off by virtue of the belt rolling under it's wheels.
I am going to assume you are all joking and too much studying has killed my sense of humour. Is this like that guy on the radio who pretends to espouse ridiculous beliefs just so listeners will call up in an outraged tizzy, so as to derive a laugh at the people who were taking it all so seriously?

Oh, ok I see now that I did not understand the question. No, the treadmill should not prevent the airplane from gaining wind speed and taking off. I first thought the question was whether the airplane could take off with no motion relative to the ground simply because it was rolling on the treadmill. lol

 
A wing produces lift from motion relative to the air, not movement relative to the ground or relative to a treadmill.
Correct ^^^ and an airplane (jet or prop) produces thrust through the air not through the ground via its wheels. It's wheels just roll along freely.

An airplane on a treadmill will not take off by virtue of the belt rolling under it's wheels.
Nope, see above.

 
Correct ^^^ and an airplane (jet or prop) produces thrust through the air not through the ground via its wheels. It's wheels just roll along freely.

Nope, see above.

Yes, I agree. I simply misunderstood the question being asked.

 
I'm with you DV,

The plane will f-ing fly. You could never spin a treadmill fast enough to make the wheels provide enough resistance to overcome the thrust of the prop. Are you guys assuming the treadmill speed goes to infinity or something?

Think about it how little force would it take to make the plane remain stationary on the moving treadmill. I havent done the calculations, but i know it is not that much. The plane is on round wheels not blocks. I know for sure that the thrust of the props is well enough to overcome the resistance of the wheels moving at a higher speed.

 
your assertion that the plane will fly only works if you change the rules and state that the conveyor can not keep up.

this discussion is predicated on the fact that the conveyor will match the thrust and prevent the airplane from moving forward.

the plane does not move forward, then no flow over the wings.

it does not take off.

 
Ok, I agree with you that if you could (some how, maybe by removing the wheels completely) make the plane stand still via the conveyor belt, then it wouldn't take off due to lack of air movement by the wings. But, I don’t think that is possible. The rolling/bearing friction will always be negligible compared to the thrust of the motor.

 
your assertion that the plane will fly only works if you change the rules and state that the conveyor can not keep up.
this discussion is predicated on the fact that the conveyor will match the thrust and prevent the airplane from moving forward.

the plane does not move forward, then no flow over the wings.

it does not take off.


this depends on the phrasing of the challenge, my understanding is that the treadmill moves backwards at the same speed as the plane's wheels roll forward.... not a a speed fast enough to to counter the speed through friction... don't overcomplicate!
Anyways, we live in a univerise governed by physics... your conveyor belt will have a top speed.

If the top speed is not fast enough to burn up the wheel bearings, we have forward motion and therefore flight.

If that top speed is fast enough to burn up the bearings, the thrust from the engine will overcome the friction between (the no longer rotating) tire and the (hauling ass) conveyer, thus forward motion, thus flight!
IT FUCKING FLYS!!!!!!!!!!!!!

 
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your assertion that the plane will fly only works if you change the rules and state that the conveyor can not keep up.
The rules are, the conveyor keeps up. No problem.

this discussion is predicated on the fact that the conveyor will match the thrust and prevent the airplane from moving forward.
Conveyor matches the "SPEED" of the airplane, not the thrust. It would have to go MANY MANY times faster than the plane to have the wheel friction match the thrust of the plane. This is where you are missing it. Thrust and Speed are quite different. If the THRUST was matched then Sapper's free body diagram would have equal forces in the horizontal direction, causing the plane to sit still. If the SPEED is matched by the conveyor, then the wheels just spin twice as fast.

 
this may be a disagreement between the theoretical and the practical.

when you run on a treadmill, it keeps up with you (or you adjust your speed to stay on)

regardless, there is no forward motion, no apparent wind created by running, so you sweat.

there is a finite amount of thrust provided by the engines, the treadmill is set to match it, and the airplane goes nowhere.

no sweat!

 
Ok, I haven't weighed in on this. So let me try (yet) another approach at explaining this in the off chance that DV is not correct in his conspiracy theory.

Let's say we have the plane sitting motionless on the conveyor. Let's say it's a small plane; small enough for a couple of people to easily push around. Now say a couple people off to the side of the conveyor (feet on solid ground) approach the plane, one on either side, and push forward equally on each wing with enough force to overcome friction. Does the plane move relative to the ground?

If you think it does not, please explain what the conveyor is doing to prevent the plane from moving when an external force is applied to it. In order to keep the plane from moving, an opposite force of equal magnitude must be applied. As far as I can see, there is no way for the conveyor to apply this force--if the conveyor moves forward, the plane moves forward with it. If the conveyor does not move, the plane rolls forward. If the conveyor moves backward (as the riddle states), the plane rolls forward with its wheels spinning faster.

If you think the plane does move relative to the ground, then (assuming no wind) it must be moving relative to the air around it as well, which I think we all agree causes lift. If you replace the force applied by the people with the thrust provided by an engine (propeller, turbine or whatever), it will still move--force is force, whether it is applied against the ground or against a fluid. And I think we all agree that if the plane can move forward it can continue to accelerate to takeoff velocity.

Please feel free to voice disagreement with anything above.

 
this may be a disagreement between the theoretical and the practical.
when you run on a treadmill, it keeps up with you (or you adjust your speed to stay on)

regardless, there is no forward motion, no apparent wind created by running, so you sweat.

there is a finite amount of thrust provided by the engines, the treadmill is set to match it, and the airplane goes nowhere.

no sweat!
Similar to what I'm trying to illustrate in my post above, the key point is the application of an external force. When you are running on a treadmill, you are applying force against the treadmill itself and you are moving relative to the treadmill but not relative to the surrounding air. The thrust from the plane's engines is not applied to the conveyor, it's applied to the air around the conveyor and thus it moves forward relative to the air.

 
^^^ Now that we've come to a consensus... Lets all watch the show, when the plane fails to take off! LOL

 
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