Bouncing ball

This is a bouncing balled experiment based on something I wrote up in physics class.

It works pretty well. Until the ball comes to a stop. Then it slips through the ground.

I'm not exactly sure why.



Also, when I wrote it up in physics class, I wrote all the Ys as Xs. If I were to have input it directly from the sheet of paper I wrote up, I'd have the ball falling sideways.