This term I'm trying to add some new elements to the Physics II lab experience. I plan on covering two labs related to a section of material then conducting a "challenge activity" during the next lab period. For example, after covering circuits and resistance, the challenge activity will be a black-box electric circuit that they have to figure out the wiring diagram for based on the information they obtained from their previous laboratory experiences. No direct instructions will be given for the challenge beyond the goal they are to accomplish. At the end of the lab period they will submit a journal of their investigations along with a short write-up of their conclusions. Okay...my question...might anyone have an idea for a challenge-type activity for vibrations, waves, & sound and for magnetism? I have the one for circuits (as mentioned) and one for light & optics but am at a loss for the other two topics.