[QUOTE=ISAtlanta300]
Quote Originally Posted by speedminded

Actually the way of propulsion is the same, that's right. However, the hovercraft or airboat has no friction. They are in essence riding on air, while the aircraft's wheels touches the ground. The hovercraft is just floating. A plane does not float. You could theoretically spin a hovercraft around like a balloon with your hands if it's floating, but not a plane.

By your definition, a speedboat would burn the same amount of fuel whether it is going up or down the river... that would not be the case.
An airboat has far more friction loss than an airplane on its free spinning wheels.

Back to the airplane:
Imagine the conveyor was flush with the ground and the transition was near seamless. The plane is taxi'ing on the runway approaching the conveyor, closer and closer, say it's going 10mph. As it goes on the conveyor that's in reverse spinning towards it is the plane going to stop or will it continue forward at 10mph?


Answer, the plane will continue forward at 10mph but the wheels will be spinning backwards at 20mph.