# A disk rotating about a point on its circumference

On a rough floor with coefficient of kinetic frction $$\mu_k$$, a horizontally placed uniform circular disk of radius $$R$$ is rotating about a fixed point on it's circumference with angular velocity $$\omega_0$$.

The time taken by the disk to stop is $$t = \dfrac{a}{b} \dfrac{\pi R \omega_{0}}{\mu_{k} g}$$, where $$a$$, and $$b$$ are positive coprime integers. Find the value of $$a+b$$.

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