ballistic

Ballistics is the science that studies the motion of projectiles, from launch to impact. It encompasses the behavior of bullets, artillery shells, rockets, arrows, and similar objects, and has applications in defense, hunting, forensic science, and sports. The field is commonly divided into internal, external, and terminal ballistics. Internal ballistics deals with events inside the firearm from ignition to the projectile leaving the muzzle, including propellant combustion, pressure development, barrel exit velocity, and barrel friction. External ballistics analyzes the projectile's flight through the atmosphere, governed by gravity, drag, lift, and lateral forces, with stability provided by spin. Drag is often characterized by a drag coefficient and the ballistic coefficient, which relate a projectile's shape and mass to its velocity loss. Weather and altitude affect trajectory, as do wind and Coriolis effects at long ranges. Terminal ballistics concerns the behavior of a projectile upon impact, including deformation, fragmentation, penetration, energy transfer, and yaw or fragmentation on target.

Measurement and modeling tools include chronographs for muzzle velocity, radar and high-speed cameras for flight observation, and ballistic software and tables that predict trajectories under specified conditions. The term also extends to forensic ballistics, which links firearms evidence to crime scenes, and to ballistic missiles, whose trajectories are designed for long-range, powered flight followed by unpowered descent.

Historically, ballistics developed from practical artillery concerns and early experiments, with formal frameworks advancing in the modern era.