Acylindrical beam of particles each with charge q and mass m has a uniform initial (charge) density p and radius r. each particle in the beam is initially traveling with velocity v parallel to the beam's axis. consider the stability of this beam by examining the forces on a particle traveling in the beam at a distance r < r from the axis (the center of the cylinder). find the approximate force on a particle at radius r caused by the other particles in the beam. you will need to use gauss's law to calculate the electric field at radius r. describe your work, and do not skip steps; show that you understand gauss's law.