A group of unknown charges are shown on the screen along with vectors representing the forces on each charge. You can click-drag on any charge to change its position.

Each charge can one of two charge magnitudes: 10.5 x 10^-6C, and 1.1 x 10^-6C. Some of the charges are positive and some are negative. Also shown is a small, blue, positive test charge.

What is the net charge of this distribution? You may neglect the charge on the blue test charge. C