# Regarding the mechanics of a Gauss Cannon

In the lab the other day, my friend and I constructed a "simple" gauss cannon consisting of 1-3 metal balls lying side by side on a bend surface and one magnetic ball lying next to one of the other balls. Then we had a final metal ball that was send down towards the remaining balls on the surface.

If we only place the magnetic ball on the surface and push a single ball down the slope towards the magnetic ball it appears that the two balls collide and freeze on the spot. The same happens is we let 1-2 balls lie alongside the magnetic ball and push a ball down towards them. The "system" of balls will slide only a little before coming to rest (We reasoned this very small displacement was due to a higher friction of the non-rolling ball system). Finally if we lay 3 balls and 1 magnetic ball on the surface and pushed the last ball down towards them we experienced the Gauss Cannon effect, where the final ball in the row was send away with high velocity.

How do you physically describe the three cases above? Why do the single magnetic ball just "drain" all the kinetic energy (and where does it go?)? Why will there be no repulsion of the outert magnetic ball if we use 1-2 balls alongside the magnetic ball on the surface? And why WILL there be a repulsion if we increase the number of balls to 3 (alongside the magnetic ball)?

Thanks!