Not so much a joke but rather a concept question:

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

If the conveyer and the plane were going the same speed in opposite directions, the plane would stay in the same place.

Pride...He's "elite" on these thinking questions...

*"elite" referring to Hackers...the movie  :bigsmile:

The plane will take off...Here is why

Lets start by looking at a car in the situation instead of a plane.  In a car, the wheels are what drives the car foward.  In this case, the car would remain in place relative to the conveyer belt due to the belt moving in the opposit direction.

Now, in the case of the plane, the wheels do no driving at all.  The wheels are only there to reduce friction between the ground and the plane itself.  The actual force that moves the plane is that of the jet engine sucking in air from the front and pushing it out the back.  

Just a little more explaining to do, and then all will be understood.

If you sit a car on an icy lake that has 0 friction between the wheels and the ice, the car will not move.  This is because the force that makes a car move the friction between the rubber tires and the ground.  With the plane, the wheels do not drive anything, they simply help the plane roll along.  So, a plane sitting on an icy lake can take off even if the wheels have no traction.

So to sum it all up...THE PLANE WOULD TAKE OFF IN THIS SITUATION.

I missed the part in the OP where it said this plane had a jet engine. Was that to be assumed?

I used that as an example, but it would be the same thing with a propeller driven plane.

So I was right? Do I win one of those cheapo Geforce 7800s?

http://www.rx7club.com/showthread.php?t=491089&highlight=engineers

my brother adds this

it does actually work.  

Let me explain differently.

The fact that the ground is moving does not matter.  The wheels are free spinning and have nothing to do with the plane actually "moving"

In order for the plane not to move, the belt would have to move ALOT faster than the plane is.  

let this video explaine it
video