Answer:
2474 m
Explanation:
You want the distance from a 30 m cliff that a cannonball fired horizontally at 1000 m/s will hit the water.
Ballistic motion
The motion of the cannonball, assuming a flat airless environment, can be described by ...
y = -1/2g(x/v)² +h
where g is the acceleration due to gravity, v is the horizontal velocity, and h is the initial height.
Solving for x when y=0, we find ...
x = v√(2h/g) = 1000√(2·30/9.8) ≈ 2474
The cannonball will hit the water about 2474 meters from the cliff.
