(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A 4.80 g coin is placed 11.0 cm from the center of a turntable. The coin has static and kinetic coefficients of friction with the turntable surface of us = 0.770 and uk = 0.400.

What is the maximum angular velocity with which the turntable can spin without the coin sliding? (In rad/s)

2. Relevant equations

Ff = FN(u)

Fa = (mv^2)/r

3. The attempt at a solution

I've always been a little foggy on rotational motion, but for this I converted the grams to kilograms and the centimeters to meters, then set the friction equal to the acceleration:

(.0048)(9.8)(.77) = [(.0048)(v^2)]/.11

Which gave me a v of .911 rad/s. I'm not sure what I did wrong/what I'm missing.

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# Homework Help: Circular motion of a coin

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