Physics Launch Speed Question?

Question

Please help me with my physics study question, I'm not sure how to set up an equation for it:?
In Denver, children bring their old pumpkins to the top of a tower and compete for accuracy in hitting a target on the ground. Suppose the tower is 9.0m tall and that the bull's eye is a horizontal distance of 3.5m from the launch point. If the pumpkin is thrown horizantally what is the launch speed needed to hit the target?

Answer 1

Vertical:
Use the distance formula in the y to find the time of flight.
s = (1/2)at^2
2s = at^2
t =√2s/a)
t = √(2(9.0)/9.8)
t = 1.35526s
Horizontal:
D = rt
r = D/t
r = 3.5/1.35526
r = 2.58m/s