After a little practice of wave superposition, I showed how waves reflect off fixed and free ends. We then went outside to watch two slinkies of different mass densities so we can see how waves reflect off the boundary between two media. I really like this particular simulation of reflections in different media to show in detail how the reflection happens. (That simulation also does a great job of reinforcing how every wave both is reflected and is transmitted at the boundary.) I then gave them time to work on a whole mess of problems to practice what we've learned.
My AP Physics C class all wanted to go to a college visit tomorrow during my class, which is when my test on kinematics was scheduled. I was OK to move it, but we talked about how we gotta schedule things early. It turns out some of them didn't know until the day before, so I got the college people to give better notification to students.