Physics
Electric field
Point charges, rods and rings: build a scene, drag it, read the field.
What happens
Point charges and the field they weave: lines flow out of positive charges and into negative ones, while the dashed equipotentials always cross them at right angles. Drag the charges around and watch the whole pattern rearrange; the presets set up a dipole, like charges and a quadrupole.
Equations used in the module
Equations E = Σ k q_i (r − r_i) / |r − r_i|³ V = Σ k q_i / |r − r_i|, E = −∇V field lines: dr/ds = E / |E|
