Water is flowing at the rate of $15 \mathrm{~m}^{3} / \mathrm{s}$ through a rectangular channel of $5$ $\mathrm{~m}$ width.
If the acceleration due to gravity $(g)$ is $9.81 \mathrm{~m} / \mathrm{s}^{2}$, the critical velocity for the flow is $\_\_\_\_$ $\mathrm{m} / \mathrm{s}$ (rounded off to three decimal places).
