1. What does the path of the puck look like? If you shift the starting point of the puck to the left or right does the path change much?
2. What type of acceleration does the puck experience-how can you tell? Hint try turning on "Show Force Vectors" in the "Display" menu.
3. In what direction does the field point between the charges?
4. Is the field zero everywhere on a line perpendicular to the joining the two charges?
5. Can you arrange the charges so the puck oscillates back and forth along a straight line in simple harmonic motion? Try various positions for the puck and try adjusting one of the glued charges. You might try the "Grid" command in the display menu to help you place your ball. There is a "Stop Ball" command in the "Options" menu.
6. What if you replace one of the static-glued charges with a charge of opposite sign? How does the motion change?