Physics propulsion question!! it's very easy :S?

A catapult on a cliff launches a large round rock towards a ship on the ocean below. The rock leaves the catapult from a height H = 32.0 m above sea level, directed at an angle theta = 47.9� above the horizontal, and with a speed v = 30.4 m/s. uming that air friction can be neglected, calculate the horizontal distance D traveled by the projectile.