A discussion of material previously covered, indicated that he was just about at the place I was at in my other physics class. In questioning him about the material, it became obvious that he had a few ideas that needed correction. We went into the lab and performed a series of quickly put together demonstrations which corrected one of these misconceptions, regarding the period of a pendulum. Returning to the classroom, and using
printouts of a sine wave, the major parts of the wave were written on the printout. These included the crests, the wavelength, the amplitude, the frequency and the period.