Answer
$39\frac{m}{s}$
Work Step by Step
We know that
$A_1v_1=A_2v_2$
$(\frac{\pi d_1^{2}}{4})v_1=(\frac{\pi d_2^{2}}{4})v_2$
This can be rearranged as:
$v_2=(\frac{d_1}{d_2})^2v_1$
We plug in the known values to obtain:
$v_2=(\frac{3.4cm}{0.57})^2=39\frac{m}{s}$
