Have you ever wondered how your mum, dad or friends can hear you? How does sound get from your mouth to their ears?
Sound starts from somewhere, for example with you, and then travels through the air like a wave. Air particles are pushed closer together and then further apart. You see the same thing with this giant slinky: not with air particles, but with rings.
If you push the button, the wave will start from you and then move further away. It’s a ‘running wave’.
You can see that the rings are pushed closer together and that this thickening runs across the slinky to the other side. The wave travels straight ahead and so do the rings, so they both move in the same direction. This type of running wave is called a longitudinal wave.
Want to know more about wave characteristics? Then take a look at Light function.
Want to know more about the other kind of running wave? Take a peek at Transversal Wave.
Longitudinal wave in an earthquake
Earthquakes create waves that travel through the earth. These include longitudinal waves, in which the earth’s crust is compressed.