Physics - NLM Question with Solution | TestHub

In the frame's reference, add the pseudo-force $ma$ opposite to the acceleration.
The incline's normal $N_1$ supports the weight
$$N_1\text{cos}30{}^{\circ }=mg.$$
Horizontally
$$N_1\text{sin}30{}^{\circ }=N_2+ma$$
where $N_2$ is the wall reaction.
The ball leaves the frame when
$$N_2=0$$
$$ma=mg\text{tan}30{}^{\circ }$$
so
$$a_{max}=g\text{tan}30{}^{\circ }=\frac{g}{\sqrt{3}}.$$
Option C.