A wave is a disturbance that moves through a medium when the particles of the medium set neighbouring particles into motion. They in turn produce similar motion in others.
Waves appear in many forms. Seismic waves shake the ground during earthquakes. Light waves travel across the universe, allowing us to see distant stars. And every sound we hear is a wave.
- Scientists use several properties to measure and describe all these types of waves. Wavelength is the distance from one point on a wave to an identical point on the next, such as from crest to crest or from trough to trough.
- Frequency describes how many waves pass one point during one second. The units for frequency are hertz