A particle has a charge of +2.1 ?C and moves from point A to point B, a distance of 0.28 m. The particle experiences a constant electric force, and its motion is along the line of action of the force. The difference between the particle's electric potential energy at A and B is EPEA - EPEB = +8.1 x 10-4 J.
(a) Find the magnitude of the electric force that acts on the particle.
(b) Find the magnitude of the electric field that the particle experiences.