Waves Flashcards
Mechanical waves
Mechanical waves need a medium to travel through and physically disrupt that mendium
Electromagnetic waves
Electromagnetic waves do not need a medium to travel through and cause magnetic and electric disruption.
Travelling waves
They carry energy through a medium without any overall movement of the medium.
What direction does the longitudinal travel in?
Parallel
What direction does the transverse wave travel in?
Perpindicular
Reflection
The bouncing of a wave off an object.
Refraction
The bending of a wave as it enters a different medium and changes speed.
Diffraction
The spreading out of a wave as it moves through a gap or an obstacle.
Interference Waves
Waves that combine to form a resultant amplitude made up of each wave’s individual amplitude.
Constructive Interference
When waves combine to form a resultant greater than each individual wave’s amplitude.
Destructive Interference
When waves combine to form a resultant smaller than each individual wave’s amplitude.
Polarisation
A wave confined to a particular plane.
Give examples of polarisation.
Sunglasses and photography
What type of wave does this phenomenon refer to?
Transverse waves.
Stationary Waves
Waves of the same frequency and amplitude that constructively and destructively interfere to produce a wave pattern in a confined space.
The Doppler Effect
The apparent change in frequency due to relative motion between source and observer.
What defines the pitch?
The frequency of a note.
What defines the loudness?
The amplitude of a note.
Quality of a note
The quality of a note is the relative strength and number of overtones present.
Intensity of Sound
The rate of sound energy incident on 1m^2 at a right angle to the direction of motion of sound.
Resonance
The transfer of energy between two bodies with the same natural frequency.
Primary colours
The three colours that combine to make white light.
Secondary colour
Combining two primary colours in equal amounts.
Complementary colours
Primary and secondary colours that combine to give white light.
Name the three primary colours.
Red, Green and blue.
Name the three secondary colours and their combinations.
red + green = yellow
red + blue = magenta
blue + green = cyan
Name the combinations of complementary colours to produce white light.
red + cyan = white
blue + yellow = white
green + magenta = white
Name the order of electrospectrum
Long waves, radio waves, tv waves, microwaves, infrared, visible light, ultraviolet, x-rays and gamma rays.
Coherent Waves
Two waves of the same frequency that are in step or a fixed amount out of step.
Give an example of a longitudinal wave.
Seismic wave
Give an example of a transverse wave.
Strings and electromagnetic waves
Describe how stationary waves occur?
They occur when a wave is confined and reflects between two boundaries.
Explain the red shift using the doppler effect.
If a visible light source is moving AWAY FROM YOU at high speed, it will appear RED.
If a visible light source if moving TOWARDS YOU at high speed, it will appear BLUE.
