Chapter 1.7, Problem 35ES

An airplane is flying at a constant height of $3000\text{ ft}$ above water at a speed of $400\text{ ft/s}$ . The pilot is to release a survival package so that it lands in the water at a sighted point $P$ .If air resistance is neglected, then the package will follow a parabolic trajectory whose equation relative to the coordinate system in the accompanying figure is $y=3000-\frac{g}{2{\upsilon }^2}{x}^2$ where $g$ is the acceleration due to gravity and $\upsilon$ is the speed of the airplane. Using $g=32{\text{ft/s}}^{\text{2}},$ find the “line of sight� angle $\theta ,$ to the nearest degree, that will result in the package hitting the target point.