1. Question: Ball A of mass ma is traveling along the x-axis with velocity vao when it strikes Ball B of mass mb, which is at rest. After the collision, Ball A travels at an angle θ above the x-axis and Ball B travels at an angle φ below the x-axis. The final velocities of Balls A and B are vaf and vbf, respectively. Write an expression that gives the velocity of Ball A, vaf, after the collision. 2. Relevant Info: Law of Conservation of Linear Momentum 3. Solution: The expression I get for vaf is vao / (cosθ + sinθcotφ). I find this expression strange because it shows that vaf is independent of the masses of Balls A and B. However, the expression for vbf does include mass. I do not understand how this makes sense conceptually -- Could someone provide an explanation?