What you were looking at is the initialization function. It just creates the three basic vectors that the bouncy ball needs: one to determine it's position, what's it's offset from the origin of the map; another to determine it's speed, how much does it move in one time unit; another to determine it's acceleration, how much does the speed change in one time unit. The fourth one has nothing to do with physics but is used as a data structure. Under it's "coordinates" it stores the IDs of the before mentioned 3 vectors.
Then you have a periodic timer that calls the function that moves the ball every time unit.