2.5 Wave Properties Flashcards
Reflection
Is the reflection of a wave when it hits a flat barrier
Refraction
IS the change in direction of a wave at the boundary between two materials caused by a change in speed
Diffraction
Is the spreading of a wave when it meets an obstacle into regions where it would not be seen if it moved in only straight lines
Wide gap produces … diffraction effect
Small
Narrow gap produces … diffraction effect
Large
Principle of superposition
If the waves from two sources occupy the same region then the total displacement at a point is the vector sum of the displacements of the individual waves at that point
What are the two different types of interference
Constructive and destructive
When two waves arrive at the same point in phase they produce …
Constructive interference, And and amplitude of 2A
When two waves arrive at the same point out of phase they produce …
Destructive interference, which will result in a smaller amplitude
Coherent
Means that there is a constant phase difference
Path difference
Is a measure of the distance between two waves arriving at a point in terms of wavelength
What does Youngs double slit experiment produce?
Bright fringes = constructive interference
Dark fringes = destructive interference
λ = aΔy / D
λ = wavelength
a = distance between the centre of slits
Δy = fringe separation
D = distance from double slit to screen
What is the historical importance of Young’s double slit experiment?
Newton said that light was particle like in nature, but this experiment proved light had wave like properties
dsinθ = nλ
d = slit width
sinθ = angle of light
n = order number
λ = wavelength
