Chapter 11 - Waves 1 Flashcards
Displacement
Distance from the equilibrium position.
Amplitude
Maximum displacement from equilibrium position.
Wavelength
Minimum distance between 2 points in phase on adjacent waves.
Period of Oscillation
Time taken for a wave to move one wavelength past a given point.
Frequency
Number of wavelengths passing a given point per unit time.
Wave Speed
Distance travelled by a wave per unit time.
Phase Difference
The difference between the peaks of two different waves.
Specular Reflection
When light hits a smooth surface, and angle of incidence = angle of reflection.
Diffuse Reflection
When light hits a bumpy surface, and it scatters.
Refraction
A wave changes direction when travelling from one medium to another.
Diffraction
When a wave travels through a gap or around an obstacle and spreads out.
Intensity
The amount of energy per second per square meter of surface.
Refractive Index
A measure of how much a substance can refract a light ray.
Snell’s Law
n1sinθ1 = n2sinθ2
Radio Waves Wavelength
10⁶ to 10⁻¹
Micro Waves Wavelength
10⁻¹ to 10^-3
Infrared Wavelength
10^-3 to 7x10^-7
Visible Light Wavelength
7x10^-7 to 4x10^-7
Ultra Violet Wavelength
4x10^-7 to 10^-8
X-ray Wavelength
10^-8 to grey area (10^-10 to 10^-13)
Gamma Ray Wavelength
Grey area (10^-10 to 10^-13) to <10^-16
Total Internal Reflection (TIR)
Occurs when light strikes the boundary between two media and is reflected not refracted.
Conditions for TIR
-Travelling from a higher to a lower refractive index.
-Light must strike the boundary at an angle above the critical angle.
Critical Angle Formula
sinC = 1/n
Describe the relationship between amplitude and intensity
Intensity ∝ Amplitude²
