(c) $F = m{r\omega}^{2}$ $= \frac{2}{125} \times \frac{1.25}{2\pi} \times (100\pi)^{2}\ \ \ (\therefore\omega = 2\pi f = 2 \times 50 \times \pi)$ $= 100\pi N = 314N$
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.