Answer
$6.73\frac{m}{s}$
Work Step by Step
According to the law of conservation of energy:
$K.E_{bottom}+U_{bottom}=K.E_{top}+U_{top}$
$\implies \frac{1}{2}mv_{bottom}^2+0=0+mgy_{top}$
This can be rearranged as:
$v_{bottom}=\sqrt{2gy_{top}}$
We plug in the known values to obtain:
$v_{bottom}=\sqrt{2(9.81)(2.3.1)}$
$v_{bottom}=6.73\frac{m}{s}$
