Question

A trolley is accelerating down an incline of angle $\theta$ with acceleration $g\sin \theta .$ Which of the following is correct? $(\alpha$ is the constant angle made by the string with vertical)

• A. $\alpha =\theta$
• B. $\alpha =0^{\circ }$
• C. $\text{Tension in the string,}T=mg$
• D. $\text{Tension in the string,}T=mg\sec \theta$

Answer 1

The correct option is A $\alpha =\theta$

Using the concept of pseudo force in the frame of trolly we have the FBD of bob as shown


$\therefore$ for the equilibrium condition along the incline
$mg\sin \alpha =mg\sin \theta$
$\Rightarrow \theta =\alpha$