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Old Nov 28, 2005 | 10:20 PM
  #116  
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Kestrel
Push to shock!
 
Joined: Sep 2002
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From: Palo Alto, CA
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Originally Posted by DakarM
Insteads of using speed like you're doing use distance. as soon as the plane moves 1inch the belt will return the plane to it's original position. The belt system will continue to do so no matter how fast the plane tries to accelerate.

That is what the question is saying no?
I believe that is probably the original intention of the question. But since I committed myself to my answer, I feel I should explain more h:

Ok so let's think about it the way you're thinking about it. Now, let's say we have a brick, and we're standing at a conveyor belt like at the grocery store. The brick is basically the plane with the brakes on; it can't roll against the conveyor. Now, let's just say for imagining it that the conveyor belt moves at a constant speed, like at the store. So, let's say you push the brick forward an inch. The conveyor moves it back an inch, just like you said. But, as you apply more and more force on the brick (which is similar to the thrust the plane's engines apply to the plane), you can hold it in a steady position, even though the conveyor belt moves in the opposite direction. If you apply even more force, it will start to move the opposite direction of the conveyor belt. Now, imagine that we adjust the speed of the conveyor belt. If the belt moves slowly, then you have to apply less force to get the brick to move against the belt. If the belt moves faster, you apply more force. The amount of force you need to apply is related to the amount of friction between the brick and the conveyor belt. If the brick were on wheels (ie like a plane on wheels), you would need even less force to move it against the belt.

That is the essence of the argument. The only thing holding the plane back is the rolling resistance drag from the wheels to the conveyor belt. As long as the engine is capable of generating enough thrust to push against the rolling resistance, the plane will accelerate.
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