mass-energy / inner product / kinetic energy / equal energy / car sitting / conservation law / energy-momentum vector / little kinetic energy / energy-momentum vector lies / energy-momentum vectors / energy inelastic collision / energy-momentum / given energy / energy-momentum relationships / energy / talking about a material object’s kinetic energy / /
equation #2: conservation of the total py Since the number of equations equals the number of unknowns, there must be one unique solution for their total momentum vector after the crash. In other words, the speed and dire