Q. When a disc is rotating with angular velocity $\omega$, a particle situated at a distance of 4 cm just begins to slip. If the angular velocity is doubled, at what distance will the particle start to slip?

A) 1 cm
B) 2 cm
C) 3 cm
D) 4 cm
Explanation

(a) Angular velocity $= \omega$
Centripetal force $F = mr\omega^{2}$
or $r \propto \frac{1}{\omega^{2}}$
$\therefore$ $\frac{r_{1}}{r_{2}} = \frac{\omega_{2}^{2}}{\omega_{1}^{2}}$
or $\frac{4}{r_{2}} = \frac{4\omega^{2}}{\omega^{2}}$
or $r_{2} = 1$ cm

Dr. Abubacker
Reviewed by Dr. Abubacker

Physics Educator & NEET/JEE Specialist

Ph.D. in Physics with 19+ years of teaching experience.