From a balistics pendulum as an example, which is probably where you are at...
Triangles, L = 12m, x_0 = 1.6, we need to find the angle (theta)
sin (theta) = 1.6/12 = 0.1333....
theta = ArcSin(0.1333...) = 0.1337 rad
Then, this is the height that the mass vertically raises in it's arc
y_2 = L-L*cos(theta) = 0.107 m
use y_2 in a kinematic swing...
v=sqrt(2gy_2)=1.45m/s