Answer
7.24 m/s
Work Step by Step
Please see the attached image first.
Here we use the Bernoulli's equation, $P+\frac{1}{2}\rho V^{2}+\rho gy = constant$
Where $P- Pressure$, $\frac{1}{2}\rho V^{2}-Kinetic\space energy\space per\space unit \space volume$, $\rho gy- Gravitational \space potential \space energy \space per\space unit \space volume.$
Let's plug known values into this equation.
$P_{a}+0+\rho gh=P_{a}+\frac{1}{2}\rho V_{hole}^{2}+0$
$V_{hole}=\sqrt {2gh}=\sqrt {2\times9.8\space m/s^{2}\times2.68\space m}$
$V_{hole}=7.24\space m/s$
