What is the second collision that occurs during a crash?

The second collision that occurs during a crash refers to the impact that passengers or occupants experience inside the vehicle after the initial impact. In this context, when a vehicle crashes, the first collision is the vehicle striking another object or surface. The second collision happens when the occupants, who are in motion due to inertia, continue moving until they come into contact with something inside the vehicle, such as the windshield, dashboard, or steering column.

This phenomenon highlights the critical importance of seat belts and airbags, which are designed to minimize the risk of injury by restraining occupants and cushioning their impact during this second collision phase. The role of the windshield or steering column as stopping surfaces underscores why safety features are essential; they can significantly mitigate the forces experienced by passengers during a crash.

The other options relate to aspects of the crash process or safety features but do not directly define the second collision itself. The focus on what happens to the occupants after the vehicle has initially struck another object clearly identifies the nature of the second collision and emphasizes the importance of understanding vehicle dynamics in crash situations.