I am working on a project for my kid. I have a question. Question: Is there a way to predict when to stop a moving ball in order for it to finally stop rolling at a specific position? Data: I know the balls x and y position, and the velocityX and velocityY float values. I think it has an accelerometer as well, but I haven't experimented with it. It has a x,y, and z value. Situation: I am programming a Sphero (wireless moving ball), and I know my starting location (0,0), and ending location eg:(0,300cm). Once it stops at the ending location, it needs to travel back to 150cm, (the middle between the two locations). But every time I find out the position is 150cm and send stop, it rolls past where I want it to go while its stopping. (Stopping Distance) I can't hard program it to stop a random SET distance (through trial and error) before the middle because its velocity won't always be the same. Sometimes it rolls on rough carpets and sometimes on smooth tile floors.