At this moment,

Forces acting on particle at \(A\) can be shown,

where, \(F=\frac{G m^2}{L^2}\)

\(\Rightarrow\) Net force will be resultant of both,

\(F_{\text {resultant }}=\sqrt{F^2+F^2+2 F^2 \cos 60^{\circ}}=\sqrt{3} F\)

\(\Rightarrow F_{\text {resultant }}=\frac{\sqrt{3} G m^2}{L^2}\)

\(a=\frac{F}{m}=\frac{\sqrt{3} G m}{L^2}\)