Ballistics is the study of projectile motion. A projectile is an object that has been launched, shot, hurled, thrown or by other means projected and which continues in motion due to its own inertia. The path of the projectile is determined by its initial velocity (direction and speed) and the forces of gravity and air resistance. For objects projected close to Earth and with negligible air resistance, the flight path is a parabola. When air resistance is significant, however, the shape and rotation of the object are important and determining the flight path is more complicated. Ballistics influences many fields of study ranging from analyzing a curve ball to developing missile guidance systems.

In order to understand projectile motion it is first necessary to understand the motion of free-falling bodies, that is objects which are simply dropped from a certain height above the Earth. For the simplest case...