An Introduction to Waves

Javascripts provided by Rainbow Arch

Wave- disturbance that travels through a medium (matter or space)

Medium- the material waves travel through

Crest- highest point of a wave

Trough- lowest point of a wave

Wavelength- distance between one point on a wave and the same point on the next wave  

Amplitude- height of a wave

Frequency- how many waves pass a certain point in a certain amount of time
                   # waves/time (usu. Seconds)

Transverse waves- particles in the medium move perpendicular to the wave

Animation by Dr. Dan Russell

Longitudinal waves- particles in the medium move in the same direction as the wave

  Animation by Dr. Dan Russell

Another great example http://members.aol.com/nicholashl/waves/movingwaves.html 

Animation by Dr. Dan Russell

Compression- “squeezed together” area in a compression wave
Rarefaction- “Stretched” area in a compression wave

What do waves transfer?  Energy

  http://home.pacbell.net/chabpyne/wrecks.html

Reflection- the “bouncing back” of a wave after striking a barrier

angle of incidence – angle between incoming wave & normal
a “normal” – a line perpendicular to the reflective surface (barrier)
angle of reflection – angle between outgoing wave & normal

angle of incidence = angle of reflection

refraction –  change of direction when a wave enters a different medium

constructive interference – 2 waves collide and build a bigger wave

destructive interference – 2 waves collide and cancel each other out

standing waves – waves that have a part that doesn’t move & other parts with increased amplitude

 Standing waves are shown on a printed page as a static, or still, diagram. Of course, like all waves, they are dynamic. This Java applet is here to help you understand how a static standing wave diagram is meant to convey the true motions of the standing wave. Understanding Standing Wave Diagrams 1