Point load simulator:

This thing simulates the movement of point loads according to Coulomb's law. All loads have mass = 1, to make simulation easier to understand in context of charges.

Use mouse left button to add a load, right click on a load will delete it, you can also drag it, and while dragging you can also change its charge using mouse wheel.
Have fun!

Appearance settings:
Color density:
Color function cut:
Display radius:

Simulation settings:
Time fragment(dt):
Calculations per frame:
Frame every: ms
Collision epsilon:

Recompute charges after collision
Recompute velocities after collision
Box settings:
Size: x
Wall restitution: 0 1

Misc settings:
Mouse wheel load 1/delta:
Add charges in range: -