Question

A pendulum of mass hangs from a support fixed. the diretion of the string when the trolley rolls up a inclination at an angle with acceleration is

Answer 1

When we the FDP, we do some components of mg and tension forces.  Now, we will acquire the relation which is given below.

You can consider the mass of pendulum as m.   When it comes to a, it is the acceleration of string.

On the other hand, g is the acceleration because of gravity. Finally, we get alpha as tan-1(a/g).

Answer 2

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