Answer
Please see the work below.
Work Step by Step
We know that
$A_1v_1=A_2v_2$
This can be rearranged as:
$v_2=(\frac{A_1}{A_2})v_1$
$\implies v_2=(\frac{d_1}{d_2})^2v_1$
We plug in the known values to obtain:
$v_2=(\frac{2.5}{2.0})^2(1.8)$
$v_2=2.8\frac{m}{s}$
