Longitudinal Wave
Direction parallel to oscillations
Transverse Wave
Direction perpendicular to oscillations
Mechanical waves
Need a medium to pass through
Polarisation
When waves are confined to one plane
Polaroid sunglasses
Absorb oncoming light while allowing vertical waves through
Displacement
distance from equilibrium
Amplitude
Maximum displacement
Wavelength
Distance between two adjacent particles
Cycle
Interval from a certain displacement and velocity to the next
Period
Time taken for one wave to pass a particular point
Frequency
Number of waves to pass a point in one second
In phase
Oscillating particles are at the same point
Out of phase
Particles with the same frequency, but at different times
Coherent
Same frequency and constant phase difference