Subcutaneous emphysema is often found in car accident victims because of the force of the crash. Chest trauma, a major cause of subcutaneous emphysema, can cause air to enter the skin of the chest wall from the neck or lung. When the pleural membranes are punctured, as occurs in penetrating trauma of the chest, air may travel from the lung to the muscles and subcutaneous tissue of the chest wall.
Both the Army and the Marine Corps teach that the maximum effective range of the M16A2/A3/A4 is 500 meters on a point target (individual enemy) and 800 meters on an area target (i.e. troops in the open).
If angle horizontal, trajectory is half parabola. Factors Influencing Projectile TrajectoryMaximum height (m)Range (distance) (m)0 1 2 3 4 5 6 7 8 9 10 11543210This scaled diagram shows the size and shape of trajectories for an object projected at 10 m/s at different angles.Factors Influencing Projectile Trajectory. Maximum height (m).actors Influencing Projectile TrajectoryMaximum height (m)Range (distance) (m)0 1 2 3 4 5 6 7 8 9 10 11543210This scaled diagram shows the size and shape of trajectories for an object projected at 10 m/s at different angles. Factors Influencing Projectile Trajectory. Maximum height (m).