What is the purpose of crush (crumple) zones, air bags, and seat belts on vehicles?
Explain Cars are made with bumpers that retract during a crash and areas of the car outside the passenger section that crush in order to increase the time of a collision thus reducing the force. A crash produces a sudden and unexpected change in momentum. This momentum change is the result of an impulse caused when the crash occurs. Since the force in the impulse is what causes damage to the people in the vehicle(s) increasing the time interval of the impulse reduces the force of the impulse. Air bags do the same thing. They, in effect, increase the time over which the driver’s and the passenger’s head move forward striking the wheel / dashboard thus reducing the force of the impact that causes damage to the head area of the body. The seat belt insures that the driver / passenger doesn’t separate from the seat of the car and experience trauma due to flying around inside the interior of the car or worse yet flying from the car and impacting on the pavement or other object which would mo
