The Physics of Automobile Accidents
Automobile accidents happen all around us. We see cars in the middle of the road after just rear ending each other. We see cars driving around town with big dents in them. Do you ever stop to wonder how car accidents happen? Physics; that’s how they happen. There are several aspects of physics that apply to automobile accidents.
An aspect of physics that is applicable to automobile accidents is kinetic energy. Kinetic energy can be defined as the energy of motion. The equation for kinetic energy is:
Kinetic energy behaves a bit differently depending on the type of collision: elastic or inelastic.
In an elastic collision, kinetic energy is always conserved. Nearly all of the kinetic energy is transferred from the first object to the second. Thus, when two cars collide, all the kinetic energy would be conserved; no energy would be lost. The objects in an elastic collision “bounce” apart when they collide. The only time that an elastic collision occurs in an automobile accident is when the vehicles collide at a slow speed.
In an inelastic collision, kinetic energy is not conserved. Some of the kinetic energy is converted into sound, heat, and deformation. The objects in an inelastic collision “stick” together. A high speed car collision is an example of an inelastic collision. The bumpers on automobiles are designed to collapse in order to create an inelastic collision. It is less damaging to the cars and to the people in the cars to allow the kinetic energy to crumple the bumper (inelastic collision) than to have the cars hit and “bounce” off of each other (elastic collision).
Momentum is another aspect of physics that is applicable to automobile accidents. Momentum can be defined as mass in motion. Everything around us has mass. Therefore, all moving objects have momentum. Momentum...