Wave Textbook Goodnotes Recap Flashcards
Progressive Wave?
A moving wave carries energy from one place to another without transferring energy to the surroundings
Wave causes?
Something making particles or fields oscillate at a source
Wave energy loss?
Oscillations pass through medium or field carrying energy and losing it as it gets further from a source
Wave behaviours?
Reflection, Refraction, Diffraction
Reflection?
When a wave is bounced back when it hits a boundary
Refraction?
Where a wave changes direction and velocity as it enters a different medium because of the change in refractive index
Diffraction?
The wave spreads out as it passes through a gap or round the obstacle
Displacement?
Has the symbol x and is measured in metres and is how far an object has moved from its undisturbed position
Amplitude?
Measured in metres with the symbol a and is the maximum magnitude of displacement
Wavelength?
Measured in metres and has the symbol λ and is the length of one whole wave oscillation otherwise wave cycle
Period?
Has the symbol T and is measured in seconds and is the time taken for a complete wave cycle
Frequency?
Has the symbol f and is measured in hertz and is the whole number of complete wave cycles or oscillations per second passing a given point from the source
Phase?
The measurement of the position of a certain point along the wave cycle and is measured in degrees or radians
Phase difference?
The amount by which one wave lags behind another wave and is measured in degrees or radians
Frequency and Period?
Inversely proportional relationships in the equation. Frequency = 1 / Period
Wave speed equation?
c = d / t
Wave speed = distance / time
c = f x λ
Wave speed = frequency x wavelength
Speed of light?
3 x 10^8 ms-1
Measuring Speed of Sound?
Microphones picking up waves from a signal generator and time and distance between microphone picking it up is recorded.
Measuring wave speed?
Record depth of ripple tank. Use a dipper to create frequency. Use a strobe light to periodically flash. Increase frequency until the same as light. Measure distance between 2 adjacent peaks.
Transverse Waves?
The direction of energy transfer is perpendicular to displacement of particles
Transverse Waves Movement?
Travel as vibrations through magnetic and electric fields with vibrations perpendicular to the transfer of energy
Transverse wave examples?
EM waves, ripples on water, waves on strings, certain types of earthquake waves (s) waves
Transverse wave graph?
Shown on displacement-time graphs and vibrations upwards from centre line has symbol a+ and downwards has a-
Longitudinal waves?
Have the displacement of particles or field parallel to the direction of energy transfer
Longitudinal waves movement?
Alternating compression and rarefaction of a medium the wave is travelling through
Longitudinal Wave graph?
Usually plotted on a displacement time graph
Longitudinal wave examples?
Earthquake waves called p waves and sound waves
Polarised wave?
A polarised wave is a wave which oscillates in a singular direction
Polarising filter?
A polarising filter can be used to polarise waves so they only travel in one direction otherwise plane
No wave polarising?
This is due to two polarising filters being at exactly 90 degrees to each other
Partial Polarisation?
This is from polarising filters not being at exactly 90 degrees or 180 degrees meaning as waves pass through their intensity is reduced
Polarisation evidence?
Only occurs for transverse waves and provides evidence for the properties of transverse waves
Light polarisation discovery?
1808 by Etienne Malus who discovered light was polarised by reflection and disproved light as longitudinal to explain polarisation
Light transverse discovery?
1817 Thomas Young suggested light could be polarised because it was transverse and consisted of vibrating electric and magnetic fields perpendicular to energy transfer
Partially polarised meaning?
Light reflected off certain surfaces
Light property?
A property of light is most light is polarised and has vibrations possible in all directions
Polarisation of light factor?
The amount of polarisation of light is dependant on its angle of incidence
Partial polarisation reduced?
Polarising filters can be used to remove the rays that can cause glare and keep necessary ones
Glare?
If partially polarised light is reflected off reflectable surfaces the unnecessary light can enter the eye causing reduction in quality of what s being seen
Polarising filter function?
If partially polarised reflected light goes through a polarising filter at a right angle you can block some of reflected light whilst letting light vibrating at filters angle however reducing intensity but reducing glare and unwanted reflections
TV and Radio signals function?
TV signals are polarised by orientation of rods on ariel being lined up with transmitting ariel. The signal strength is determined on ariels positioning or tuning
Superposition?
When 2 or more waves pass through each other
Superposition resultant?
At the instant the waves cross the displacements due to each wave combine and then continue on their way
Principle of superposition?
When 2 or more waves cross the resultant displacements equal the sum of the individual displacements
Interference?
The superposition of two or more waves combing constructively or destructively
Constructive interference?
If wave displacements are in the same direction a bigger displacement occurs and this caused by a trough becoming larger by meeting another trough
Total destructive interference?
This is where equal and opposite displacements meet and cancel each other out completely
In-Phase?
When two points are at the same point in a wave cycle and have the same displacement and velocity
Superposed points?
In phase waves constructively interfering with each other
How is a complete wave cycle shown?
It is shown as a multiple of 2π or 360 degrees
What is phase difference on wave?
How far 2 points are apart on a wave cycle and is measured in degrees, radians, fractions
Exactly in of phase?
0 degrees phase difference or 360 degrees phase difference or Odd number of radian multiples or 180 degrees
Stationary wave?
Also called a standing wave. It is the superposition of two progressive waves with the same frequency, wavelength and amplitude and move in opposite directions
Resonant Frequency?
Frequency at which the original wave and reflected wave combine with an exact phase difference of half or complete wavelengths
Stationary wave property?
Stationary waves are transverse waves, form from 2 waves interfering, only formed at resonant frequency
Nodes?
The point at which amplitude is 0 on a stationary wave and where there is total destructive interference
Anti-nodes?
The point of maximum displacement of a stationary wave and where there is total constructive interference