# Help with minor car crash physics

1. Feb 6, 2004

### noobie_physics

Hello,

I am new to forums so please excuse my post if it is in the wrong area.

I was wondering whether someone could help me out with understanding the physics involved in a minor car crash between 2 cars (both travelling at 5 mph).
*This is not homework etc, trying to understand a real life accident.

I have started to read up on some areas e.g. Mass of cars, Velocity and Kinetic Energy but need help sticking it all together - unless someone is willing to show me the calculations involved and work it out?(should be able to provide details required).

TIA for any information or pointers.

Kind Regards,
Rhys.

2. Feb 6, 2004

### turin

To simplify, consider if it is elastic or inellastic. At 5 mph, it is probably pretty elastic. So, momentum and kinetic energy will be conserved to a high degree (this is just an assumption). You could also take a different approach and consider a different question to answer: how elastic/inelastic is the collision. Then, you could make a calculation for the results of an elastic and an inelastic collision, and compare to the actual results of the collision. You also should probably consider the friction between the cars and the road, and rotational kinetic energy I think should be included as a deviation from perfectly elastic behavior.