I posted this again because the first video I posted is not working for me. It's taking forever to load. That video is a combination of three clips mixed together. The video labeled Ball Drop is just one of the clips. Basically it shows how she figured out where to put the balls and how she knows to track them as they roll down the different ramps. She also knows to get the ball from the exit at the bottom. However this particular clip doesn't show everything obviously. I didn't want to import all three videos separately.
FYI: I hate that Photobucket will nto let me add comments when I import my video to Blogger.