Since the ball was launched horizontally u_y=0, we know that a_y=-9.81 and s_y=-1.3 and we are tying to solve for t.
possible methods are:
Finding velocity using the equation v^2=u^2+2as then subbing velocity into v=u+at to find time
or
subbing the values into s=ut+\frac{1}{2}at^2, and then...