Answer
The required speed is
$$v=2200\text{ m/s}.$$
Work Step by Step
The horizontal component of the velocity is constant so it is simply $$v_h=3.60\text{ m/s}.$$
The vertical component of the velocity is due to gravitational acceleration. Since there is no initial velocity in the vertical direction, we have for the final value of the vertical component:
$$v_v=2gh.$$
This gives for the speed
$$v=\sqrt{v_h^2+v_v^2}=\sqrt{v_h^2+(2gh)^2}=\sqrt{3.60^2+(2\cdot9.81\cdot108)^2}\text{ m/s}=2200\text{ m/s}$$
