A Method of Estimating Velocity in a Car Crash

摘要

In car crash accident investigation, estimating car's velocity is important. We are interested -in two cars' crash accidents. When we can find skid marks of braking in the scene of an accident, we can estimate the velocities of the cars. But it is becoming difficult to find them because of a lot of cars with ABS. We propose a method of estimating velocities and directions of cars without information from skid marks of braking. In our method a conservation law of angular momentum is important as well as that of linear momentum and energy. Firstly we demonstrate that angular momentum is conserved in a real car crash experiment. Then we analyze it and propose our method.