Experimental study of the coefficient of elastic restitution in collisions using video-analysis

In this article, we conducted a brief discussion of the laws of conservation of linear momentum and energy in mechanical collisions. We presented some experimental procedures to confirm these conservation laws in various situations involving collisions. The law of conservation of momentum will be directly verified by measuring the objects’ velocities, while for the law of conservation of energy, we explored the concept of the Coefficient of Restitution. We will obtain the experimental values of the motion variables using video analysis and the free software Tracker. We analyzed binary collisions between two identical bodies, oblique rigid collisions of a body with an immovable surface, and frontal rigid collisions of a freely falling body with a horizontal surface. For these cases, we examined the dependence of the coefficient of restitution on the collision angle or the impact energy. We found that the coefficient of restitution varies with energy, being lower for higher energies, implying that we move away from the regime of linear elasticity as the collision energy increases.

Keywords:
Conservations laws; collisions; coefficient of restitution