In: Physics
A potter's wheel—a thick stone disk of radius 0.500 m and mass 125 kg—is freely rotating at 50.0 rev/min. The potter can stop the wheel in 6.00 s by pressing a wet rag against the rim and exerting a radially inward force of 72.0 N. Find the effective coefficient of kinetic friction between the wheel and rag.
Initial angular velocity of the wheel, 
To convert rev/min to rad/s. Multiply by 
Final angular velocity, 
Time, 
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Radius of the disk, 
Mass of the disk, 
Radial inward force, 
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First, find angular deceleration
Use formula 






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Consider the disk
Net Torque = Moment of inertia*Angular acceleration



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Frictional force = Coefficient of friction* Radial force
Moment of inertia of the solid disk, 
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Cancel the negative sign.



ANSWER: 
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