Question

a canon is shot horizontally at 15 m/s off a cliff, which is 36m above water. how far away from the cliff should the target enemy boat be when the canon is shot?

Answer 1

the horizontal speed is constant.

So, how long does it take to fall 36 meters?

h(t) = 36 - 4.9t^2

As to the distance of the boat, it depends on the goal: hit or no hit?

Answer 2

The goal is to hit I believe.