Transverse vs. Longitudinal (Compressional) Waves (with springs)
To demonstrate the differences between transverse and longitudinal waves.
One spring (the slinky, long spring, or two cones connected by a spring will work)
Take the spring you are using and stretch it out across the room. Show the transverse wave by moving you hand rapidly up and down creating a wave. The wave should be visible above and below the original position of the spring. Next pull some of the coils of the spring towards you and then release. This wave should be along the original path of the spring.
When using the long spring make sure that the spring is held by the circles on the ends or the spring may be damaged. The two cones connected by the spring creates sounds with each wave and can be used to show reverb. The slinky performs best when it is on a table. Hold on end of the slinky and initiate either type of waves from the other end of the slinky.