posted by Lindsay .
A helicopter is flying in a straight line over a level field at a constant speed of 21.7 m/s and at a constant altitude of 11.5 m. A package is ejected horizontally from the helicopter with an initial speed of 21.6 m/s relative to the helicopter, and a direction opposite to the helicopter's motion. Find the initial speed of the package relative to the ground.
I thought I knew how to do this...until I saw that they give an altitude. Can someone give me the first steps? I can probably get it after that.