# Help rolling mill!

1. Aug 29, 2004

### dibilo

a rolling grain mill having radius R is constrained to roll in a circle of radius r at a constat angular speed of W by a rigid shaft of negligible moment of inertia. For what value of W will the mill stone push on the floor with a force equal to twice its weight?

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my problem... i dont understand the question. does the question suggest that the faster the mill rolls, the larger the downward force? as in normal? pls offer your guidance and tell me what are the things i should look in order to solve this question. thx in advance...

2. Aug 29, 2004

### Beer-monster

As the mill spins is exert and inward and thus an outward force of mw^2r (I hope that right never did get the centrifugal/centripedal difference). Therefore at some speed w the wheel will exert and outwards force equal to its weight and thus push dowonwards with twice its weight (and no net force up).

Well thats my interpretation, but I'm a dope so I could be wrong ^__^