Physics - Rotation Question with Solution | TestHub

The correct option is (C). Concept: The angular speed is given by $\omega =\frac{\Delta \theta }{\Delta t}$ Relative angular speed is given by, $\omega ={\omega }_{\mathrm{s}}-{\omega }_{\mathrm{h}}$ The angular speed of the second dial is ${\omega }_{\mathrm{s}}=\frac{2\pi }{60}=\frac{\pi }{30}\mathrm{rad}/\mathrm{s}$ The angular speed of the hour dial is ${\omega }_{\mathrm{h}}=\frac{2\pi }{3600\times 12}=\frac{\pi }{21600}\mathrm{rad}/\mathrm{s}$ Therefore, relative angular speed is given by, $\omega ={\omega }_{\mathrm{s}}-{\omega }_{\mathrm{h}}=\frac{\pi }{30}-\frac{\pi }{21600}=\frac{719}{21600}\mathrm{rad}/\mathrm{s}$