Tzz in Maxwell's stress tensor quantifies the force per unit area in the z direction on an area element aligned with the z-axis, even when the electric field along z is zero in electrostatics. This phenomenon arises from the electromagnetic field's interaction across surfaces, rather than from forces acting on charge distributions. The analogy of a box under pressure illustrates how forces applied in the x and y directions can create pressure in the z direction on the top and bottom surfaces.
PREREQUISITESPhysicists, electrical engineers, and students studying electromagnetism and continuum mechanics will benefit from this discussion.
Can I use the analogy with a box when you apply forces on x and y directions on its sides but not on the top and bottom there will be pressure on the z direction on the top and bottomOrodruin said:It is not a force on a charge distribution. It is the force of the EM field on one side of the surface acting on the EM field on the other side.