Please wait for the animation to completely load.

In the animation the electric potential changes from 0 V to 1 V as shown by the equipotential lines (position is given in meters, time is given in seconds, velocity is given in meters/second, and electric potential is given in volts). Click-drag to place the 1-mC test charge anywhere in the animation before you press "play." What is the mass of the particle? Restart.