Analysis of Three-Particle Elastic Collisions Using Newtonian Mechanics and Vector Geometry

We study one-dimensional elastic collisions of three point masses on a line under vacuum, with no triple collisions. We express momentum conservation in matrix form and analyze the composite map $D=D_{BC}D_{AB}$ and its powers $D^k$, which yield the velocities after any prescribed number of collisions for arbitrary mass ratios and initial data. After that, using vector $u$ on a plane $s^\perp$, the total number of collisions is $$n\;=\;1+\Big\lfloor\tfrac{\Omega-\phi_{BC}}{\theta}\Big\rfloor+\Big\lceil\tfrac{\Omega-\phi_{BC}}{\theta}\Big\rceil,$$ Through this concept, $D$ is recognised as giving $u$ a rotation with angle $\theta$ which is determined by only mass ratios. And, we calculated energy transfer through collisions. With the work, we find that the change of energy is proportional to total momentum of two particles and average velocity of particles based on initial average velocity of A and B before collision.