### Five Charges

### Description:

Five unknown charges are shown on the screen along with vectors representing
the net forces on each. The length of the vector is proportional to the
magnitude of the force. You can click-drag on any charge to change its position.

### Question 3:

Which charges have like signs? How did you arrive at your answer?

### Questions 4:

Move charges a and b to the far left of the window and the other three
charges to the far right. What can you say about the force on charge a as
compared to the force on charge b (is Newton's third law obeyed)? Now move
one of the other three charges closer to the pair on the left. Why are the
forces on a and b no longer equal and opposite?