1) To bring a window into the forground click on the window. With the SimPhysics window in the foreground, bring up the Fields Equations box by going to the "Camera" menu and select "Show Equations For > Electric Field...". (The ">" means it is a hierarchical menu selection.)
2) You may have to move the Equations window so that you can see both SimPhysics and the Field Equations at the same time. If you click on other windows, the SimPhysics and Field Equations windows will move back and you will have to click on them to bring both to the foreground.
Answer the questions below and record your answers in your journal.
1. How many places can you find where absolute value of the x component of the electric field is about 0.3. What do these places have in common?
2. How many places can you find where the electric field has only a y component? ...only a x component? What characterizes these places?
3. How many places can you find where the electric field makes a 45 degree angle up from the positive x direction?
4. How many places can you find where the electric field is zero? Keep in mind that the computer cuts off the field when you get too close to a charge because of the 1/r squared divergence. Very close to a charge the magnitude of the field becomes large.
5. In what direction does the electric field point between the two charges? How is this direction related to the direction of the deflection of the puck for exercise two?
6. Now choose "Show Vector graph" from the Camera menu. Review you answers to questions 1-5. Try dragging one of the charges around.
7. Choose "Hide Vector Graph" from the Camera menu. Choose "Show Plot" from the Camera menu. The color mix (RGB value) is determined by the relative strength of the field from each charge.
8. Choose "Use Color Strength Plot" from the Camera menu. How does this plot differ from the plot in question 7?