@Ynotgo Usually, in Honors Physics for freshmen, special relativity is covered in the first mechanics class. One of the reasons, besides the fact that it is really “mechanics”, is that magnetic fields are introduced in the second (E&M) class as a transformation of electric fields in a moving reference frame (c.f. Purcell E&M). Engineers (other than engineering physics) usually do not need as in depth a treatment and may be just lightly exposed (or not at all) to special relativity in the regular Physics for Engineers course.