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Old 03-06-2006, 07:20 AM
David Simmons David Simmons is offline
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Join Date: Nov 2001
Posts: 12,684
Originally Posted by zut
I'm assuming a system where the force from the engine thrust is balanced by the force transmitted through the wheels due to the acceleration of the treadmill (and the inertia of the wheels).

I'm not sure what calculation to do here, because the most applicable calculation is the one that you did yourself in the other current thread. Just take a look at that calculation and ask yourself what would happen if the treadmill accelerated more than the acceleration required to keep the plane stationary.
I think you're right. No matter the details of the mechanization, an acceleration of 1245 rad/sec2 is needed to balance a thrust of 500 lb given the assumed wheel inertia. That means that the wheel and the conveyor will almost instantly, say within 1.5 sec., reach entirely unrealistic speeds. As far as I'm concerned that makes BR#2 a fantasy world scenario.