Yep. That was Sully's point.

Why? What relevance has that got?

Which would move the plane horizontally, just like my balloon. The wheels only hold the plane up off the ground.

It's also like maglev trains, which need no contact with the ground to move forward with an external force (in this case a magnetic force).

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that is not possible.

go to a sporting good store or your garage

find a roller skate or blade

put a hand in it, and with your other hand move the wheels

is your hand in the skate pulled by the wheels?

or are you just making the wheels spin?

and.. your free hand is the conveyor

Here is my postulate.

A 747 cannot take off without moving forward relative to the ground, however the speed at which its wheels spin on a treadmill do not have any affect on the 747 moving forward.

Due to the structure of the question, it is impossible for the plane to move horizontally.

I answered Sully.

I guess some of you are missing something. Force vs. resistance produces equal and opposite reactions. The exact same force that causes the wheel to turn also causes the treadmill to turn at the exact same time. There's no "this then that."

Independently, I agree. But the sum of the wheel speed and the treadmill speed determine the plane's speed.

Only because the force can't be transferred to the ground because of the spinning treadmill?

Well you could design bearings that had more friction, but that would then be the bearings that was keeping the plane from taking off instead of the treadmill.

No. The treadmill matching the speed of the wheels ensures that the wheel hubs will not move in relation to the ground. Unless the landing gear breaks, this means that the plane will not move in relation to the ground.

I also think that momentum and inertia may have something to do with it. The original question didn't ask if the plane is moving when the treadmill started up, or if they started at the same exact time and kept the same exact speed throughout.

It doesn't depend on the design of the bearings, as long as they are not ideal frictionless bearings. Yes, it would be the friction from the bearings keeping the plane from taking off, but the friction force only exists due to the speed at which the wheel is spinning, which is caused by the design of the treadmill.

Then where does the force of the engines go? If they are thrusting at so many pounds against the air, there has to be an equal force against the plane to keep it from not moving. That means you are saying that the treadmill is exerting the same force against the plane as the engines, but since the wheels are spinning, how can that be? They would have to have tremendous friction to match the engines' force.