Hey everyone, Reviewing material for a technical interview and I have stumbled into some problems that I sadly have issues with. Old review for me :D. Any help would be appreciated. I can follow up through the conservation of energy equation. However at the in an elastic collision line, I do not know why those are being subtracted. That would not seem to follow the conservation of momentum since the masses are not the same. assuming i can get that part, the Vo = v - V is just substituted into the simplified conservation of momentum equation? Is nothing done with the conservation of energy equation?