Answer
$v_0 = \sqrt{2gh +\frac{R^2g}{2h} }$
Work Step by Step
We know from the values of the x and y components of velocity that:
$v_{xo} = R\sqrt{\frac{g}{2h} }$
And:
$v_{yo} = g\sqrt{\frac{2h}{g} }$
That simplifies to:
$v_0 = \sqrt{2gh +\frac{R^2g}{2h} }$
