Abstract
Improving methods of reconstruction of road accidents that lead to establishing the conditions and factors that led to the production of collision, is a challenge and involves using in the mathematical models similar to the collision, only the parameters that reflect better the energy exchange during of development of the collision, so finding a mathematical model for determining the initial angle and the impact velocities which are based on the restitution coefficient relation will lead to results with a high degree of accuracy.
The study suggets finding a mathematical model for determining the initial collision angle and the impact velocities that will be validated by a collision test between two models will apply the theory of similarity,thus the two models will be treated as two prototypes that have similar characteristics as real cars. So, in order to notice the conditions of similarity it is necessary to observe simultaneously the conditions of the geometry assimilation, the kinetic and dynamic similarity of the phenomenon of collision.
Keywords: direction of velocity differences, angles, restitution coefficient, impact, scale of similarity.