In this work, three instances are discussed within electromagnetism which highlight failures in the
validity of Newton’s third law, all of them related to moving charged particles. It is well known
that electromagnetic theory paved the way for relativity and that it disclosed new phenomena which
were not compatible with the laws of mechanics. However, even if widely known in its generality,
this issue is not clearly approached in introductory textbooks and it is difficult for students to
perceive by themselves. Three explicit concrete situations involving the breaking of Newton’s third
law are presented in this paper, together with a didactical procedure to construct graphically the
configurations of electric field lines, which allow pictures produced by interactive radiation
simulators available in websites to be better understood.