This activity is a great way to start off your unit on waves. There is a vocabulary page where the students can learn the words associated with waves (frequency, crest, trough, wavelength, medium, amplitude). Once the students have done the vocabulary worksheet, then they are prepared to complete the lab portion of this lesson.
The purpose of the lab is to teach students the relationship of wavelength and frequency. It is a wonderful visual to show students when energy is added, then the wavelength gets shorter. The other great thing about this lab is the materials for the lab are easy to get. All you need is a jump rope, a long piece of butcher paper, and a meter stick.
The activity is great to use at the beginning of a unit on sound waves as well because you can talk about how the waves on the jump rope are exactly like sounds waves (the longer the wavelength, the lower the pitch, etc).