From Mechanics

As the brick has no speed at the start

\displaystyle \text {KE = KE gained}.

\displaystyle \begin{align} & \text {KE gained=PE }\text{ lost }=\text{2}\times \text{9}\text{.8}\times \text{3}\text{.2}=\text{62}\text{.72 J} \\ & \\ & \frac{\text{1}}{\text{2}}\times 2{{v}^{2}}=62\textrm{.}72 \\ & v=7\textrm{.}92\text{ m}{{\text{s}}^{\text{-1}}} \end{align}