I think we need to get them to do it, I still dont think it would actually take off.

The force that moves the plane forward is on the body of the jet where the engine attaches. Forward motion of a wing causes lift. The wheel speed is not a factor at all. I suppose if it was really fast, the wheels could fall off. That would stop liftoff.

This has been kicked around the forums for a while.
I like the guys drawing
The jet plane will take off because it is irrelavant how fast it is going in relation to the ground as it is not driven by wheels but by jets (hence the name of the craft). It'* wheels will be spinning like a raped ape but it will have it'* normal airspeed and thus take to the air like, well, a jet. It better have some good wheel berings and some well balanced wheels.

If the plane does not use it'* jets it will not move therefore the treadmill will never need to turn. If it uses it'* jets it will begin to move forward, as it moves forward the treadmill will begin to move backwards twice as fast as the jet is moving forward. The jet will continue to accelerate gaining airspeed while the tradmill continues to accelerate twice as fast as the jet. Eventually (slightly longer than normal due to added rolling resistance) the jet will take off. It really does not matter how fast the ground appears to be passing by because like I stated, ground speed is irrelevant. The jets push air not ground so who cares if it is on a treadmill.

???? It just seems to me when u yourself is running on a treadmill u don't feel wind no matter how fast u are running? I would think in that case that the plane would have to double it'* normal takeoff speed to get enough lift??

The plane will take off. The thrust is applied to the AIR behind the plane, not the ground.

The treadmill will have no effect (or very little, based on the friction of the wheel bearings).

Trust me on this one guys.

Let'* throw another one out.

A box truck loaded with canaries and cages weighs EXACTLY 5000 pounds. The truck hits a bump, scares the canaries, and they all take flight in their cages. While the birds are airborne, does the truck weigh the same?

Weight is a function of gravity. Which point are we referring to while the vehicle is in the air?

Hmmm! Very thought provoking. I would say the truck would still weigh the same cuz the birds are trapped in the cages on the truck. But it made me wonder if all the birds got scared and start flying in the same direction would they be able to fly off of the truck? ( I watched Finding Nemo the other day and the fish got loose cuz they all swam down to keep from being hoisted up)

if the truck is sealed, it will weight the same, if it is not sealed, it will weight a little less.

Now the drawing makes sense! If something is attached to the plane like that, than yeah, the thrust would make the plane lift off the gorund and take off. But if the plane was set on the treadmill like we would be running on it, then no, it would not take off, that would mean it could hover in one postition, and I am not seeing a big ole' jet do that anytime soon!

I think the plane if it was doing 2mph and the tradmill was doing 2mph the would equate 4mph to the speedometer......so even though the plane is actually doing the speed for takeoff the speedometer is reading double, on do airplanes judge by wind speed and not wheel speed?