Dynamics, plane drops mass trajectory question

[cd80187]

Homework Statement

The pilot of an airplane, carrying a package of mail, wishes to hit recovery location A. Assume that the plane is traveling at constant speed of 200 km/hr at a constant height of 100m above the ground. What angle theta with the horizontal should the pilot's line of sight to the target make at the instant of release?

Homework Equations

I don't understand what equations to use, if you could help that would be awesome.

The Attempt at a Solution

 

[teknodude]

Just start with the equations of motion under gravity, or you could use the already derived free fall equations, but its better start from scratch and derive it. They tell you that speed is constant, so what are the acceleration components?