Waves Flashcards
Define a Cycle
One complete vibration of a wave
Define displacement
How far a point has moved
From its undisturbed position
Define Amplitude
Maximum magnitude of displacement
From 0
Define period
Time taken per wave cycle
Seconds
Define frequency
Wave cycles per second
Hertz
Define phase
A measurement of the position of a certain point along the wave cycle
Define phase difference
Amount that one wave lags behind another
In degrees/radians or fraction of wavelength
Define reflection
Wave changes direction at a boundary
Define refraction
Wave enters different medium (of different n)
Changes speed and
Bends towards/away from the normal
Define a progressive wave
A wave that transmits energy from one place to another
Without transmitting matter
How is a stationary wave produced?
Two identical progressive waves (of same wavelength)
Travelling in opposite directions
Superimpose
What is the principle of superposition?
When two waves meet
Total displacement at any point = sum of individual displacements at that point
Define a longitudinal wave
Particle vibrations(energy transfer) parallel to direction of movement
Define a transverse wave
Particle vibrations(energy transfer) are perpendicular to direction of movement
What is coherence?
When 2 waves have the same frequency and constant phase difference
