the principle of superposition the resultant displacement at any point is the sum of the separate...
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The principle of superposition
The resultant displacement at any point is the sum of the separate displacements due to the two waves Eg: with a slinky coil spring
The principle of superposition
The resultant displacement at any point is the sum of the separate displacements due to the two waves Eg: with a slinky coil spring
supercrest
The principle of superposition
The resultant displacement at any point is the sum of the separate displacements due to the two waves Eg: with a slinky coil spring
supercrest
The principle of superposition
The resultant displacement at any point is the sum of the separate displacements due to the two waves Eg: with a slinky coil spring
Two square waves superposing:
Two square waves superposing:
Two square waves superposing:
Superposition of sine waves:
Superposition of sine waves:
Superposition of sine waves:
A square wave can be made up from several sine waves
of higher frequencies
Phase changes on reflection
LONGITUDINAL PULSE TRANSVERSE PULSE
Phase changes on reflection
LONGITUDINAL PULSE TRANSVERSE PULSE
Phase changes on reflection
LONGITUDINAL PULSE TRANSVERSE PULSE
Phase changes on reflection
LONGITUDINAL PULSE TRANSVERSE PULSE
Interference effects
Two dippers in a ripple tank can cause circular wavefronts to re-inforce or cancel:
Re-inforcement(constructive interference)
Cancellation(destructive interference)
Interference effects
Two dippers in a ripple tank can cause circular wavefronts to re-inforce or cancel:
Re-inforcement(constructive interference)
Cancellation(destructive interference)
Coherent sources (of the same frequency and phase relationship) produce a stable interference pattern.
Experiments with microwaves:
a) The intensity of the receiver signal decreases with distance from the transmitter.
x
x
Signal strength
Experiments with microwaves:a) The intensity of the receiver signal decreases with distance from the transmitter.b) Microwaves are reflected off metal plates – similar to light on a mirror.
x
x
Signal strength
Experiments with microwaves:a) The intensity of the receiver signal decreases with distance from the transmitter.b) Microwaves are reflected off metal plates – similar to light on a mirror.c) Diffraction occurs at each slit (slit width is of similar magnitude to the wavelength)
x
x
Signal strength
Experiments with microwaves:a) The intensity of the receiver signal decreases with distance from the transmitter.b) Microwaves are reflected off metal plates – similar to light on a mirror.c) Diffraction occurs at each slit (slit width is of similar magnitude to the wavelength)d) An interference pattern forms with regions of constructive and destructive interference
Regions of reinforcement
Experiments with microwaves:a) The intensity of the receiver signal decreases with distance from the transmitter.b) Microwaves are reflected off metal plates – similar to light on a mirror.c) Diffraction occurs at each slit (slit width is of similar magnitude to the wavelength)d) An interference pattern forms with regions of constructive and destructive interference
Regions of reinforcement
Experiments with microwaves:a) The intensity of the receiver signal decreases with distance from the transmitter.b) Microwaves are reflected off metal plates – similar to light on a mirror.c) Diffraction occurs at each slit (slit width is of similar magnitude to the wavelength)d) An interference pattern forms with regions of constructive and destructive interference
Regions of reinforcement
Regions of cancellation
compressions
rarefaction
Two loud speakers emitting the same note can cause loud and quiet areas in front
of the speakers
compressions
rarefaction
Regions of reinforcement (LOUD)
Two loud speakers emitting the same note can cause loud and quiet areas in front
of the speakers
compressions
rarefaction
Regions of reinforcement (LOUD)
Regions of cancellation (QUIET)
Two loud speakers emitting the same note can cause loud and quiet areas in front
of the speakers
When compressions (or rarefactions)
arrive in phase from both speakers,
constructive interference occurs,
creating a loud region
