Question

A pendulum of mass $m$ hangs from a support fixed to a trolley. The direction of the string (i.e.., angle $\theta$) when the trolley rolls up a plane of inclination $\alpha$ with acceleration ${}^{\prime }{a}^{\prime }$ is

• A. Zero
• B. ${\tan }^{-1}\alpha$
• C. ${\tan }^{-1}\frac{a+g\sin \alpha }{g\cos \alpha }$
• D. ${\tan }^{-1}\frac{a}{g}$

Answer 1

The correct option is C ${\tan }^{-1}\frac{a+g\sin \alpha }{g\cos \alpha }$