Answer:
Trajectory of a bullet in flight is governed by a combination of the initial speed, the ballistic coefficient of the bullet, the angle at which it is fired, and external factors such as air temperature, humidity, wind speed, and air pressure. Ballistic coefficient is a value assigned based on the bullet shape and its length to diameter. A bullet with a higher ballistic coefficency will retain energy (speed) better than one with a low BC. There are several computer programs that can be used in the speed and BC (the major factors) are known.