Seat belt 012 Other parts of this chapter will explain in more detail how to maximize your safety. However, note that it is impossible to completely avoid casualties in a serious collision even if the seat belt is correctly worn and the airbag has been deployed. Why always wear seat belt Physical principles of frontal collision 1 Seat belt can reduce impact injury of the passenger as much as possible by reducing passenger's forward movement inertia when a front collision of the car occurs. The panssenger without seat belts are not "combined" with the vehicle, and still move forward at the speed before the collision during decelerating in the event of a frontal collision.
The principle of collision physics described in the example not only applies to frontal collision of the vehicle but also to all the types of other vehicle collisions. While driving, both the vehicle and the panssenger have energy (kinetic energy) which depends on the vehicle speed and the panssenger’ mass. The larger the vehicle speed and the mass, the more the energy upon impact. In which, the vehicle speed is decisive. For example, the released kinetic energy at 50km/h is 5 times that at 25km/h.