waves revision Flashcards
Define wave
transfer of energy and momentum from one point to another without any transfer of matter
define progressive waves
where there is a net transfer of energy from one point to another
Define mechanical waves
require a material medium (sound, water)
Define electromagnetic waves
waves which can travek through a vacuum (light, x-rays)
define longitudinal wave
direction of vibration of the particles is parallel to the direction of energy transfer (sound)
define transverse wave
direction of vibration of the particles is perpendicular to the direction in which the wave travels (em waves)
define frequency
the number of waves passing a point per second
define period of a wave
the time taken to produce one complete wave
what are the displacements of a longitudinal wave described as
compressions and rarefractions
define phase difference
the fraction of a cycle between two particles.
1 wavelength =360 or 2pi radians
order of waves (^wavelength)
Radio, micro, infra-red, visable, ultraviolet, x, gamma
define stationary waves
waves where there is no net transfer of energy and momentum from one point to another
define node and antinode
node - no displacement
antinode - max displacement
define coherent
2 waves that have the same frequency, wavelength and a constant phase difference
when is there destructive interference
(n+0.5)wavelength
