Answer
$4.12*10^{-3} m^3/s$
Work Step by Step
We find the velocity out of the pressure head as:
$v^2= 2gh$
$v=\sqrt{2*9.8*12} = 15.96m/s$
To get $m^3$ we need to multiply by the area
$v * A = 15.96 * (.0185/2)^2 *3.14) = 4.12*10^{-3} m^3/s$