A projectile is an object that is propelled by the application of an external force and then moves freely under the influence of gravity and air resistance.

Although any objects in motion through space are projectiles, they are commonly found in warfare and sports (for example, a thrown baseball kicked a football, fired a bullet, shot an arrow, or stone released from a catapult). 

In ballistics, mathematical equations of motion are used to analyze projectile trajectories through launch, flight, and impact.