Get Understanding Car Crashes It's Basic Physics Video Discussion Questions Answer Key

3:23 25:25 Understanding Car Crashes: It's Basic Physics - YouTube YouTube Start of suggested clip End of suggested clip Now watch what happens when the car crashes into the barrier. The front end of the car is crushingMoreNow watch what happens when the car crashes into the barrier. The front end of the car is crushing and absorbing. Energy which slows down the rest of the car.

A key concept in collision vehicle dynamics is the conversation of energy and momentum. Momentum is the product of mass and velocity and is always conserved in impacts. This means that forensic engineers can calculate the velocity of vehicles before a collision by knowing their speeds after the impact and vice versa.

The physics of a car collision will never, no matter how energetic, emit a completely new car. The car would experience exactly the same force in both cases. The only force that acts on the car is the sudden deceleration from v to 0 velocity in a brief period of time, due to the collision with another object.

The object that was struck will either absorb the energy thrust upon it or possibly transfer that energy back to the vehicle that struck it. Focusing on the distinction between force and energy can help explain the physics involved. Car crashes are clear examples of how Newton's Laws of Motion work.

Elastic Collision Provided that there are no net external forces acting upon the objects, the momentum of all objects before the collision equals the momentum of all objects after the collision.

Crash force is equal to your body weight multiplied by the speed of the vehicle.

As every action results in an equal and opposite reaction, your speed at the point of impact (and the weight of the object you hit) will determine how much force it exerts on your car. An object light enough to move when you hit it will absorb some of your kinetic energy, thus limiting the severity of the collision.