Don't worry Shattered, I wrote 'simple' at the end of my post as an act of facetiousness after typing a quite convoluted explanation, British
humour
I don't know if I can get my viewpoint across to you in simple terms because its not really simple, like you say, however, here goes.
Yes, I agree that the conveyor belt is moving backwards and all that but he question is 'are the wheels trying to push the plane forward?' If the
answer was 'yes' then the plane would remain stationary and rooted to the ground because their motion is cancelled out.
BUT the answer to this is 'no' because the propeller is pulling it forward and the wheels are just like the castors on an office chair. Therefore
because the wheels are not the driving force it matters not a jot what the belt is doing. The analogy that was posted earlier about it being like a
plane on skis taking off from ice sort of works quite well because that illustrates how the prop is pulling the plane along all by itself without any
influence from anywhere else, the whole bit about wheels and converyor belts is a red herring, the propeller imparts the speed that makes the plane
fly, not the wheels.
Where it gets a bit more complex is that as the plane starts to move forward the reversal of the belt WILL keep it stationary until, that is, the
engine could be revved up enough to overcome this, therefore at full throttle the plane will actually move physically forward at an ever increasing
speed until take off speed is reached, only the wheels will accelerate twice as fast, but to no avail.
I've probably made the whole thing worse now, oh dear.
edit to remove the evidence of an inability to type and think at the same time.
[edit on 15-2-2006 by waynos]
