Question

A plumb bob is hung from the ceiling of a train compartment, The train moves on an inclined track of inclination ${30}^0$ with horizontal. The acceleration of train up the plane is $a=g/2$. The angle which the string supporting the bob makes with normal to the ceiling in equilibrium is

• A. ${30}^0$
• B. $\tan {}^{-1}\left(2/\sqrt{3}\right)$
• C. $\tan {}^{-1}\left(\sqrt{3/2}\right)$
• D. ${\tan }^{-1}\left(2\right)$

Answer 1

The correct option is B $\tan {}^{-1}\left(2/\sqrt{3}\right)$