With this simple spring it is easy to demonstrate transversal and longitudinal waves to your students. The light material allows you to demonstrate the waves in the air without tangling the spring. Expands from 20 inches to 12 feet. Experiments on transversal waves include: Observing phases of reflected waves. Measuring wave velocity. Investigating the relationship between wavelength and frequency of a standing waves. Experiments on longitudinal wave include: Observing longitudinal waves (compressional waves) and phase of reflected waves at a fixed end. Measuring the velocity of a longitudinal waves.