Q 11-04-135JEE MainJEE Main 2022 (25 Jun, Shift 2)Easy
A disc with a flat small bottom beaker placed on it at a distance $R$ from its center is revolving about an axis passing through the center and perpendicular to its plane with an angular velocity $\omega$. The coefficient of static friction between the bottom of the beaker and the surface of the disc is $\mu$. The beaker will revolve with the disc if:
Answer: (B) $R\le\dfrac{\mu g}{\omega^2}$
Static friction must supply the centripetal force: $m\omega^2R\le\mu mg\Rightarrow R\le\dfrac{\mu g}{\omega^2}$.
Solution by Sreeraj P, M.Sc Physics