Shooting is a popular activity and enjoyed by many people, so much so that it is also practiced at a competitive level. Although many people have fired a gun, few actually realize how much physics is involved in shooting. So, what exactly is ballistics? Ballistics is the science or study of the movement of projectiles and in the case of most firearms, those projectiles are the bullets. There are two things that affect the trajectory of a bullet once it has been fired from the weapon. These elements are the drag of the air on the ball and the force of gravity acting on the ball. The force of gravity acting on the ball is always in a constant direction, which is downward, at a speed of 9.81 m/s^2. However, the drag force of the air on the ball is not always in a constant direction. This is because the trajectory of the ball changes, so the direction of air drag on the ball also changes. So what determines the trajectory of the bullet once it leaves the barrel? Besides gravity, these are the weight, shape and speed of the ball....