Q. A particle is tied to $20cm$ long string. It performs circular motion in vertical plane. What is the angular velocity of the string when the tension in the string at the top is zero
A) $5\ rad/sec$
B) $2\ rad/sec$
C) $7.5\ rad/sec$
D) $7\ rad/sec$
Explanation
(d) $\omega = \sqrt{\frac{g}{r}} = \sqrt{\frac{9.8}{0.2}} = 7rad/s$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.