Demonstration of momentum and kinetic energy during an entire collision

A collision is a physical phenomenon commonly occurring in our daily life. In the classroom, the instructor usually demonstrates collision to enhance students' conceptual understanding of momentum conservation and kinetic energy conservation in collisions.^1–3 The results of such demonstrations illustrate that the total linear momentum and the kinetic energy for elastic collisions in a system are similar both before and after the collision.⁴ Demonstrating the momentum and kinetic energy while the two objects are in the process of colliding can provide greater insight into these concepts. Such demonstration results during the collision are rarely described, however, because the time during the collision process is very brief, making the determination of the velocity or momentum of each object very difficult.⁵ In this paper, we intend to present an interactive demonstration⁶ proposed to illustrate the results of momentum conservation and kinetic energy conservation simultaneously for the entire collision.