Waves

• Amplitude

  A wave’s maximum displacement from its equilibrium position.
• Antinode

  A position of maximum displacement in a stationary wave.
• Coherence

  Waves are coherent if they have the same wavelength and frequency, as well as there being a fixed phase difference between them.
• Diffraction

  The spreading of waves as they pass through a gap of similar magnitude to their wavelength.
• Electromagnetic waves

  Waves that consist of perpendicular electric and magnetic oscillations.
• Frequency

  The number of waves that pass a point in a second

  period =1/frequency
• Period

  The time taken in seconds for a wave peak to travel the distance of one wavelength.
• Interference

  The name given to the superstition of waves that occurs when two waves meet. If the waves are in phase they will constructively interfere, but if they are out of phase, they will destructively interfere.
• Longitudinal wave

  A wave with oscillations that are parallel to the direction of energy propagation. sound waves are an example of a longitudinal wave.
• Node

  A position of minimum displacement in a stationary wave.
• Path difference

  A measure of how far ahead a wave is compared to another wave, usually expressed in terms of wavelength.
• Phase difference

  The difference in phase between two points on a wave. It is usually expressed in radians
• Phase

  A measure of how far through wave’s cycle a given point in the wave is.
• Polarisation

  The restriction of a wave so that it can only oscillate in a single plane. This can only occur for transverse waves.
• Wave speed

  The product of a wave's frequency and wavelength.
• Stationary wave

  A wave that stores, but does not transfer energy

  There is no net transfer of energy and momentum from one point to another
• Progressive wave

  waves were there is a net transfer of energy and momentum from one point to another.
• Transverse wave

  A wave with oscillations that are perpendicular to the direction of energy propagation. Electromagnetic waves are examples of transverse waves.
• Wavelength

  The distance between two identical positions on two adjacent waves. It is commonly measured from peak to peak or trough to trough.