1. Choose the initial velocity by moving the initial velocity slider. (Firefox will implement sliders in Firefox 23. For now, a text box is provided.)
2. Click on the Play button to start. The ball machine will toss the ball straight up. The blue arrow is the ball's velocity vector, and the magenta arrow is the ball's acceleration vector.
3. To stop the ball near the top, click on the box "Stop at the top ". To continue after the ball reaches its highest point, click on the Play button.
4. To repeat the animation, click the Reset button.
5. To control the animation speed, move the frames per second (FPS) slider.