Find the minimum acceleration of the wedge so that block under free fall

$\begin{array}{l}forwedgex=\raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$2$}\right.a{t}^2\to 1\\ forblockh=\raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$2$}\right.g{t}^2\to 2\\ \frac{x}{h}=\frac{a}{g}\Rightarrow a=g\left[\frac{x}{h}\right]butfromfig \hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\cot \theta =\frac{x}{h}\\ \therefore a=g\cot \theta \end{array}$