How do you possibly infer?

If I wasnt clear enough - do the said experiment with open palm - plane resting on the palm. <img src="/forums/images/graemlins/rolleyes.gif" alt="" />

The prime mover is indeed coupled to the treadmill thanks to gravity - the entire craft is one body, one object, one piece of mass - how are the wheels magically independent of the rest of the mass that it shares?

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