The techniques of that is the seat belts use pre-crash tensioners. Within milliseconds, seat belt pre-tensioners tighten safety belts and help prevent belted occupants from sliding and bouncing around during a crash. The seat belts allow passenger to decelerate with the car during the collision instead head on collision with windshield or steering wheel. The seat belts also have a property to bend when crashing. So it increases time in impulse therefore decreases force impact on human.

Inertia safety belt reels occurs approximately 6 milliseconds after full frontal impact. Approximately 4 milliseconds later before the head and chest begin to move forward, the air bag sensors trigger the front air bags and the small pyrotechnic charges in the pre-tensioners, which minimize any slack in the safety belt and n

The necessary first attribute of an effective head restraint is good geometry. If a head restraint isn't behind and close to the back of an occupant's head, it can't prevent a "whiplash" injury in a rear-end collision. A restraint should be at least as high as the head's centre of gravity, or about 9 centimetres (3.5 inches) below the top. The backset, or distance behind the head, should be as small as possible.

Crumple zone is very effective way of absorbing the force before its impact passes straight inside the vehicles onto the passengers.

egate the effects of bulky or layered clothing. The front air bags take approximately 35 milliseconds to fully inflate, which is completed just before the occupant meets the bag, approximately 50 milliseconds after impact.

Between 45 and 70 milliseconds after impact, ensuring that the cross belt pressure against the occupant's chest remains fairly constant. By avoiding peak loads, the potential for chest injury in very severe impacts is reduced. The function of inertia reel safety belts in effective, it can fasten you to the seat when crashing. The seat belt allows you to travel at the same speed with the car instead of throwing you out toward steering wheels, it can also trigger airbag to inflate.

Bumpers on today's cars generally consist of a plastic cover and underneath, a reinforcement bar made of steel, aluminium, fibreglass composite, or plastic. A bumper system also should include mechanisms that compress to absorb crash energy, polypropylene foam or plastic honeycomb are often used. For a bumper to be effective, there must be some distance between the reinforcement bar and the car surface.

Some common words found in the essay are:
Bumpers Bumpers, Devices Seat, Airbags Inflating, Crumple Zone, Windshield Cars, seat belts, head restraint, steering wheel, crumple zones, tempered glass, steering control, force impact, changing momentum increased, people hard interior, results force acting, results force, force acting, reinforcement bar, hard interior surfaces, front air bags,
Approximate Word count = 1279
Approximate Pages = 5 (250 words per page double spaced)