What I am understanding for this experiment is that the plane will be going takeoff speed, but the conveyor belt will going the EXACT same speed in the opposite direction. The question is (under my understanding) "Will the plane be able to take off?"
If this is correct, then that would mean that the question IS NOT "Will it move forward". Of course it will move forward, if the plane goes faster then the belt. But they are supposed to me matched for speed. And if the speed of the PLANE itself (regardless of wheel speed) is matched to the speed of the conveyor belt. IT WILL NOT BE MOVING (as relative to a stationary object) and therefore mean NO air movement over the wings, and plane will not take off.
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Now it would be different if the plane was already flying. The belt speed would have no relevance to the plane at that point. But since there is a connection to the belt (via the wheels) it does have to overcome the speed of the conveyor belt all together, but it would be going faster then the belt and the experiment wouldn't be valid.