Solution to Fun with Fundamentals Puzzler: This ship is a-sailing

The cannon, which sits at sea level, has a velocity of 82 m/sec.

At what angle must the cannon be elevated to hit the pirate ship?

We know that the maximum range is attained at 45° — so the ship is well within the range of the cannon.

Maximum range = Rm = 822 x 2 · 0.5 ÷ 9.8 = 686.12 meters.