Waves Flashcards
Types of waves
Electromagnetic and mechanical
Electromagnetic waves are
Oscillating electric and magnetic fields that progress through space without the need for a substance.
Longitudinal waves
Waves in which the direction of vibration is parallel to the direction of travel
Example of longitudinal wave
Waggling a slinky back and forward, sound waves and primary seismic waves.
Transverse waves
Waves which the direction of vibration is perpendicular to the direction in which the wave travels.
Examples of transverse waves
Electromagnetic waves, secondary seismic waves and waves on a string/wire.
What type of wave is plane polarised
Transverse
How to make polarised light unpolarised
Use a Polaroid or polarising filter
Equation for phase difference
2 πd / λ
180 degrees in radians
π
360 degrees in radians
2π
90 degrees in radians
π/2
Reflection
Light bouncing off surface and reflecting at the same angle
Refraction
When a wave passes a boundary where it slows down and changes direction
Diffraction
A wave spreading out after passing through a gap
Transmission
When a wave (like light) passes through a medium
Absorption
When a substance captures energy from a wave
Scattering
When light changes direction due to imperfections in the medium
Superposition
The combination of waves as they pass through each other
When a crest meets a crest
Super crest
When a trough meets a trough
Super trough
Destructive interference
When a peak meets a trough (phase difference of pi)
Constructive interference
When a peak meets a peek (No or 2pi phase difference)
Stationary wave
A wave where it forms areas of maximum displacement and no displacement
Progressive waves
Conventional wave with no defined areas of superposition
First harmonic
The simplest stationary wave pattern on a string
Node
No displacement
Antinode
Area of maximum displacement.
What is the equation for first harmonic on closed closed system
L=1/2 wavelength (add half for each harmonic after)
What is the equation of the first harmonic of a open open system
L=1/2 wavelength (add half for each harmonic after)
What is the equation for the first harmonic of a open closed pipe
L=1/4 wavelength
What is the job of an oscilloscope
To interpret waveforms
