Progressive Wave
Wave that transfers energy without transferring material, made up of a medium or field oscilating
Amplitude
Waves maximum displacement
Frequency
Number of wave oscilations passing a point per second
Wave Length
The length of one whole oscilation
Speed
Distance travelled by the wave per unit time
Phase
The position of a certain point in a wave
Phase Difference
How much a particle/wave lags behind another particle/wave
Period
Time taken for 1 full oscilation
In Phase
- 2 points are in phase when they are both at the same point of the wave cycle
- same displacement and velocity
- phase is multiple of 2π
- same frequency and wavelength
Transverse Waves
Oscillation of particles is at right angles to the direction of enery transfer
Longitudinal Waves
Oscilation of particles is parallel to the direction of enery transfer
- made up of compressing and rarefractions
- cant transfer in a vaccum
Polarised Wave
- Oscilates only in one place
- Only transverse
- Provides evidence for the nature of transverse waves
Polaroid Sunglasses
Reduce glare by blocking partially polarised light as they only allow oscilations in the plane of the filter
TV and Radio Signals
Plane polarised by the orientation of the rods, transmittging and recieving aerial must be aligned in the same plane to recieve the same
Super Position
- When the displacement of the 2 waves are combined as they pass each other
- Resultant displacement is the sum of each waves displacement
Constructive Interference
When 2 waces have displacement in the same direction
Deconstructive Interference
- When one wave has positive displacement and other has negative displacement
- If they have equal but opposite displacements, total destructive interference occurs
Stationary Wave
- formed from the superposition of 2 progressive waves, travelling in opposite directions
- no energy is transferred
How stationary microwaves are formed
- by reflecting a microwave bean at a metal plate
- to find the nodes and antinodes use a microwave probe
How stationary sound waves are formed
- place a speaker at one end of a closed glass tube
- lay powder in the tube
- power will shake at the nodes and be stationarry at the antinodes
Path Difference
Difference in the distance travelled by 2 waves
Coherent Light Source
Same frequency and wavelength and fixed phase difference
- EG Lasers
