"Robert M. Gary" wrote:

Only if there is an 80 mph tailwind.

If the plane is rolling 80mph against a conveyor going 80mph back the
difference would be zero.

True. But I was referring to the problem stated, that the conveyor was
moving the same speed and opposite direction to the speed and
direction that the plane was MOVING, not this different scenario in
which the conveyor was moving the opposite direction and same speed to
that at which the plane's tires were turing.

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