The exponential function model of radioactive decay and the concept of a half-life are used in nuclear experiments that appear in introductory and intermediate laboratories. In our interactions with students, we have found that students at all levels have significant confusion about both the term exponential and what is meant by a half-life as…

Discusses the teaching of vectors and the inadequate and inappropriate examples given in many textbooks. Suggests using the motion of a sailboat or the motion of a car moving on the Earth's surface as possible examples. Details a proper vector teaching example. (MVL)