A cannon mounted on a pirate ship fires a cannonball at 125 m/s horizontally, at a height of 17.5 m above the ocean surface. Ignore air resistance. (a) How much time elapses until it splashes into the water? (b) How far from the ship does it land?

Answer 1

(a) Since there is no initial vertical velocity component,
H = (1/2) g t^2
(The height above water is H.)
t = sqrt(2H/g) = 0.529 s

(b) 0.529 s * 125 m/s = 66.1 meters

The cannonball would have travelled much farther if it had been pointed upward.