Equivalence of total force (and torque) for two formulations of the Lorentz law

摘要

Two formulations of the Lorentz law of force in classical electrodynamicsyield identical results for the total force (and total torque) of radiation ona solid object. The object may be surrounded by the free space or immersed in atransparent dielectric medium such as a liquid. We discuss the relation betweenthese two formulations and extend the proof of their equivalence to the case ofsolid objects immersed in a transparent medium.