In an atomic physics experiment, two atoms collide with each other in such a way that the initial total momentum of the atoms is zero. The atoms are chosen so that M2= 2.0 M1.
In the collision, the atom M1 has a final velocity, V1f= - 0.25 V1j. What is the ratio of the final kinetic energy to the initial kinetic energy of the system (the two atoms)? In other words, what is KEfinal/ KEinitial in this collision?