Question

A plumb line is suspended from a ceiling of a car moving with horizontal acceleration of a. What will be the angle of inclination with vertical

• A. $\tan^{- 1}(a/g)$
• B. $\tan^{- 1}(g/a)$
• C. $\cos^{- 1}(a/g)$
• D. $\cos^{- 1}(g/a)$

Answer 1

Answer: (A)

$\tan^{- 1}(a/g)$

Answer 2

From the figure

$\tan\theta = \frac{a}{g}$

$Q = \tan^{- 1}{}(a/g)$