Will It Take Off?

[theeloved1]

This has been making quite a stir on many forums recently. Haven't seen it here...thought I'd get the debate started here

A plane (747 passenger jet) is sitting on a runway that can move (some sort of band conveyor). The plane moves in one direction, while the conveyor moves in the opposite direction. This conveyor has a control system that tracks the planes speed and tunes the speed of the conveyor to be exactly the same (but in the opposite direction).

The question is:

Will the plane (747 passenger jet) take off or not?

[kompressornsc]

You might want to look here to see what fellow Autopians thought last week.

[theeloved1]

just came back to delete this thread because I found it...computer has been down for awhile...didn't search originally...

[Neothin]

I dont think I got in on the action last time so here's my thinking on it:

Planes are propelled by their engines. These engines don't supply power to the wheels. The wheels are free rotating. Because of this, if the runway is moving in the opposite direction of travel, the only thing that would happen is that the wheels would spin twice as fast as the plane is moving forward. it would still have a net forward motion because the jet engines are pushing the plane forward, not the wheels. If this was a car, or any other vehicles that use their wheels to propel them forward, the forward motion of the car plus the equal reverse motion of the conveyor belt would equal out to a net movement of zero. But like I said, the wheels on a plane aren't powered, they just sit there and spin. Unless the wheels blow up from spinning to fast, this plane will take off