have been trying to make me own workig newton cradle. I know some physics. the problem is that my balls don´ta completely stop moving after the coalition, they rather continua their movement but with a reduced violocity. This typ of movement increases and grows with the number of coalitions. At the end all of the balls move with eatch other. And thats not what i want. The balls i have been using are glas or stone balls. I could not get my hands on metal balls. Can that be the reason for this failure?