Question

A simple pendilum is set up in a trolly which moves to the right with an acceleration $a$ on a horizontal plane. Then the thread of the pendilum in the mean position makes an angel $\theta$ with the vertical

• A. ${\text{tan}}^{-1}\frac{a}{g}\text{in thebackward direction}$
• B. ${\text{tan}}^{-1}\frac{g}{a}\text{in thebackward direction}$
• C. ${\text{tan}}^{-1}\frac{g}{a}\text{in the forward direction}$
• D. ${\text{tan}}^{-1}\frac{a}{g}\text{in the forward direction}$

Answer 1

The correct option is A ${\text{tan}}^{-1}\frac{a}{g}\text{in thebackward direction}$

As we know,
$\text{tan}\theta =\frac{ma}{mg}=\frac{a}{g}$
$\theta ={\text{tan}}^{-1}\left(\frac{a}{g}\right)$
Final answer: (b)