Thread: Physics Quiz 3
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Unread 20-11-2011, 09:28
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Re: Physics Quiz 3

Quote:
Originally Posted by Ether View Post
Yes.

But according to the Coulomb friction model, the total friction force must be mu_k*W.

So that means tau_k must equal mu_k*W*r*sinθ.

So, what happens if the voltage to the motor is increased?

This doesn't sound right to me. The torque applied by the motor should not be changing as theta changes. I think the problem is that in order to find the friction equal to tau_k/(r*sin(theta)), you must assume the wheel is gripping. This does make sense because it is able to rotate and drive around the pivot but is inconsistent. I feel like one of the boundary conditions is actually overconstraining the model.