Laws of motions
Fimpact=maaverage=m ∆v/∆t
The above equation is rather important. In below, we will talk about the safety measurement in modern cars, and the theory behind of them can be explained by this equation. This equation is derived from Newton second law F=ma, and the acceleration also can be derived to be change in velocity divided by change in time. When collision occurs, the impulse(Fimpactt) is constant, hence the only factor we can change is the time impact time. The longer the impact time, the weaker the impact force.
3.1 Crumple zone (Caleb)
All of the cars nowadays have crumple zone, it is just a matter of large and small. Generally safer car has a larger crumple zone. Crumple zone is an indispensable safety feature in cars. We can observe in most of the car the engine is located in front, and the rear is usually a luggage compartment. …show more content…
Since when collision occurs, the car will decelerate rapidly, because of inertia, the passenger will lean forward. Seat belt will stop the passenger from leaning and maintain the same deceleration as the car. When the belt is pulled vigorously the retractor will lock the belt and prevent passenger from hitting the interior of the car. [7]
3.4 Materials of car (Caleb)
The material used in the car is the key factor of car's safety. Nowadays usually made of steel, aluminium, and even hybrid of metals.
Material contributes to the rigidity of the vehicle, better materials used in car can prevent the collapse of structure. In other words, the stiffer the car, the less crumple when it collides.
Nowadays car manufacture is working hard on developing materials that is stiff yet light also cost effective. For example, BMW has recently developed a material which is a hybrid of carbon fibre and plastic. It has the stiffness of carbon fibre and yet has the sheer strength of