Longitudinal (Compression) Waves
A longitudinal (compression) wave is formed by squeezing together material as the wave moves through it. These are waves in which the particles of the medium vibrate back and forth along the path that the wave travels.
To see an example of a longitudinal wave, do the following demonstration.
Creating Longitudinal WavesFor this activity you need a spring toy such as a Slinky. A piece of rope will also work if you can’t find a spring toy. Have someone hold one end of a spring toy, such as a Slinky, and stretch it between you at least two metres along a smooth, flat surface. While your assistant holds one end, perform the following task. From your end of the spring toy, push it straight toward the other end. Watch closely and you will see a compressed wave travel from your end to your assistant’s end. Note which direction your arm is moving. Is it moving in the same direction as the wave or the opposite direction? |