I teach some basic (and a tiny bit more advanced too) physics to third year Chemistry students (Chem 326) . For some of the lectures such as the one about wave propagation I gave this week, I use this (generally good) book: Fundamentals of Physics, Wiley, 8th Edition, by David Halliday, Robert Resnick, Jearl Walker.
As I have only a small group of students, it is a rather interactive format which allows questions. The figure below, from the above book, is, I think, incorrect. I asked the students why, and, through discussions, one of the student made the prediction that we should never observe a pool mirage when driving down hill. Do you agree?