Q. A car is moving in a circular horizontal track of radius $10\ m$ with a constant speed of $10\ m/sec$. A plumb bob is suspended from the roof of the car by a light rigid rod of length $1.00\ m$. The angle made by the rod with track is
A) Zero
B) $30{^\circ}$
C) $45{^\circ}$
D) $60{^\circ}$
Explanation
(c) $\tan\theta = \frac{v^{2}}{rg}$
$\therefore\theta = \tan^{- 1}\left( \frac{v^{2}}{rg} \right) = \tan^{- 1}\left( \frac{10 \times 10}{10 \times 10} \right)$
$\therefore\theta = \tan^{- 1}{(1) = 45{^\circ}}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.