Q. A particle is moving with a constant speed $v$ in a circle. What is the magnitude of average after half rotation?
A) $2v$
B) $2\frac{v}{\pi}$
C) $\frac{v}{2}$
D) $\frac{v}{2\pi}$
Explanation
(b) $Time\ T = \frac{2\pi r}{v}$
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$and\ t_{0} = \frac{T}{2} = \frac{\pi r}{v}$
$\therefore\ v_{av} = \frac{2r}{\pi\ r/v} = \frac{2v}{\pi}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.