but the wheels do not mater when talking about airplanes. you are thinking of a car on a treadmill.

[quote]the plane does not use its wheels to plropell itself forword.[/quote]

Exactly!

where did you get the commit about the break?

[quote]i think we need a geek in here with some numbers about how the belt will cancle out each pound of the airplane going however fast on a treadmill going the same speed in the oposite direction.[/quote]

That's easy: It won't.

You "no-flyers" keep thinking you can subtract one speed from the other, get a result of zero, and say "therefore the airplane is not moving!" Wrong.

[quote]No, if the conveyer is going 100mph backwards, the plane would be going 100mph forwards and the wheels would be spinning at 200mph.[/quote]


no, the wheels are moving at 100 miles an hour, if you had a radar gun on the plane then it would be zero... think about it being this way... the plane is moving a 100mph by itself, not on the conveyor, seperately the conveyor is moving at 100mph, set the plane on the conveyor and the plane is sitting still although the wheels are now moving at the 100 mph instead of the plane

"run with it"

That is mechanical energy. Now, try running through the air. The mechanical energy, from the treadmill, cannot counter the plane's thrust.

i did not say the part about the subtracking the speed to get the resualt of zero.

[quote]no, the wheels are moving at 100 miles an hour, if you had a radar gun on the plane then it would be zero... think about it being this way... the plane is moving a 100mph by itself, not on the conveyor, seperately the conveyor is moving at 100mph, set the plane on the conveyor and the plane is sitting still although the wheels are now moving at the 100 mph instead of the plane[/quote]

No. A car-style speedometer attached to the airplane's wheels would read 200 mph. The airplane's true ground speed would still be 100 mph.

[quote]Why would the brake be on if he was trying to take off?[/quote]


no one said anything about a brake, you are twisting words

[quote]i did not say the part about the subtracking the speed to get the resualt of zero.[/quote]

"Cancelling" is the same as "subtracting" in this case.

The belt cannot "cancel" the airplane's movement by moving backwards at the airplane's speed. Nor at any other speed for that matter.

i have to go now. i am sad that i am leaving this very interesting argument.

Here is something for you people that believe that the airplane cannot move itself forward on the belt and fly.

So far we have had several people convert from believing that the airplane cannot move itself forward on the opposite moving belt and fly, to believing that it can move itself forward on the belt and fly.

I don't think we have ever had anyone convert from will-fly to no-fly.

Why do you think that is? Do you think if people argue the no-fly side for too long that they just suddenly turn stupid?

Think about it like this.. If i was running with a grocery basket on that same huge conveyer belt and it was matching the speed of me (and the basket) i would be going nowhere right? right. Now.. i step off of the conveyer belt but still holding on to the grocery basket that is still on the conveyer, i start walking, i can now move the cart forward on the conveyer because my feet are not pushing off the conveyer anymore, they pushing off something totally seperate. Just like an airplane that doesnt rely on the treadmill to push off of, it pushes off the air to move the plane.

[quote]No. A car-style speedometer attached to the airplane's wheels would read 200 mph. The airplane's true ground speed would still be 100 mph.[/quote]


no, because if the plane is moving in the air it doesnt use the wheels, the wheels are free moving, so the plane is moving by the power of its engine, and is not using the wheels, but when you put the wheels on the conveyor they start moving and gravity takes over and the plane's engine is still working hard to propel it that 100 mph but cant because... so this would be a great way to land a plane

[quote]no, because if the plane is moving in the air it doesnt use the wheels, the wheels are free moving, so the plane is moving by the power of its engine, and is not using the wheels, but when you put the wheels on the conveyor they start moving and gravity takes over and the plane's engine is still working hard to propel it that 100 mph but cant because... so this would be a great way to land a plane[/quote]

You are so close to figuring out why you are wrong about this.

[quote]no one said anything about a brake, you are twisting words[/quote]

A airplanes wheels only have 2 settings, brake and nuetral, Do you agree? If the wheels are not in neutral then the brake is on. If the brake is not on then the wheels are in neutral.

There is no motor attached to the wheels in any way.

If you can't run through air, then you can't counter the thrust of a plane.

[quote]quote]No. A car-style speedometer attached to the airplane's wheels would read 200 mph. The airplane's true ground speed would still be 100 mph.[/quote]


no, because if the plane is moving in the air it doesnt use the wheels, the wheels are free moving, so the plane is moving by the power of its engine, and is not using the wheels, but when you put the wheels on the conveyor they start moving and gravity takes over and the plane's engine is still working hard to propel it that 100 mph but cant because... so this would be a great way to land a plane
[/quote]

When an airplane is rolling on a runway (or on a treadmill) it is not using the wheels for motive power, but a speedometer driven by a cable attached to a wheel will most certainly register the airplane's ground speed.

Therefore the readings would be as I described. The movement of the conveyor belt would INCREASE the "wheelspeedometer" reading but would not affect the airplane's true movement at all.

No, it won't work to land the plane either. Say you touch down on the conveyor at 100 mpn, the conveyor moving backwards at 100 mph... the airplane will still have 100 mph ground speed. Braking to a halt would be darned tricky. Assuming a SHORT conveyor, though, it would roll right off the end of the conveyor, and assuming this was flush with the normal runway surface it could brake normally.

[quote]A airplanes wheels only have 2 settings, brake and nuetral[/quote]

Ah, not quite, there is a full range of brake pressure between "full braking" and "no brakes at all" just as in a car. This doesn't affect the problem, though, as the brakes are off when takeoff is attempted.

[quote]thank you whendricks, atleast someone understands that the airplane needs lift to take off.[/quote]

That's right...pat yourselves on the back for not being able to distinguish the difference between a car's mode of propulsion and an airplane's mode of propulsion.