Final answer:
Trajectory and shooting scene analysis is based on the study of external ballistics, which involves the motion of projectiles and the external forces acting upon them.
Step-by-step explanation:
The analysis of trajectory and shooting scenes is based on the study of external ballistics. External ballistics involves the study of the motion of projectiles, including factors such as their trajectory, range, and time of flight. It focuses on the interactions between a projectile and the external forces acting upon it, such as gravity, air resistance, and wind.