WAVES & WAVE PHENOMENA A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z                    HOME ABOUT CATEGORIES SITE MAP COPYRIGHT ADVERTISE CONTACT entire Web this site wave A disturbance that travels from one place to another without actually transporting any matter. The source of all waves is something that is vibrating, moving back and forth at a regular, and usually fast rate. Waves have high points called crests and low points called troughs. The vibration between two extreme points – the crest and the trough – is generally an "oscillation." Amplitude refers to the maximum distance on either side of the midpoint of the wave. The distance from the top of one crest or tough to the next is called the wavelength. How frequently a point on a wave passes a particular point per unit time is described by its frequency. The unit of frequency is the hertz (Hz) after Heinrich Hertz. Once per second is 1 hertz, twice per second is 2 hertz, etc. The time it takes for an object to make a complete vibration – for instance, the time it takes a pendulum to swing once each way – is called its period. Frequency and period are reciprocals of each other. Related category    • WAVES AND WAVE PHENOMENA Source: U.S. Centennial of Flight Commission Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) BACK TO TOP