Waves Flashcards
Total internal reflection
Angle of incidence > critical angle
Radio wave
10^3
Microwave
10^-2
Infrared
10^-5
Visible light
0.5 x 10^-6
Ultra violet
10^-8
X-ray
10^-10
Gamma
10^-12
Progressive wave
An oscillation through matter transferring energy
Transverse wave
Oscillations perpendicular to wave propagation
Longitudinal waves
Oscillations parallel to wave propagation
Displacement
Distance from equilibrium position in particular direction
Amplitude
Max displacement from origin
Wavelength
Min distance between two adjacent points on a wave oscillating in phase
Period
Time taken for a complete oscillation of 1 wavelength to pass a given point
Frequency
Number of complete oscillations passing given point per unit time
Wave speed
Distance travelled by wave per unit time
Phase difference
Difference in displacement of particles along a wave - measured in radians
Reflection
When a wave changes direction at a boundary between two media
Refraction
When a wave changes direction and speed when entering a new medium
Polarisation
Occurs when oscillating wave is restricted to only one plane
Principle of superposition
When two waves meet at a point, the resultant displacement is equal to the sun of individual wave displacements
Coherence
Two waves are coherent when they have a constant and unchanging phase difference
Maximum displacement
n number of wavelengths
Minimum displacement
Odd number of half wavelengths
Stationary wave
Two progressive waves with same frequency/ travelling in opposite direction superpose. Stationary wave formed has a series of alternating nodes and antinodes
Techniques to investigate superposition and wavelength
Sound waves = two audio signal generators - both emit coherent waves which overlap and form interference pattern
Light = young double slit - laser produces monochromatic light producing two coherent waves which overlap and superpose (create alternating bright and dark fringes)
Wavelength = diffraction grating
