i don´t quite understand: if you have a system made up of three pool balls. one of them is moving with a speed of 1 meters per second, the two other balls are standing still. if the moving ball hits the two other balls, in a way that the moving ball is standing still afterwards, then the two other balls should have a speed of 0.5 meters per second each, so that momentum is conserved in this system, right? if that is the case than there is a loss of kinetic energy, because 1 ball moving at a certain speed has double the kinetic energy, than two balls moving at half the speed? but energy is supposed to be conserved in a system two. can someone please help get rid of that twist in my head, what am i getting wrong here? is momentum not being conserved in a system?