Waves Flashcards
What is a wave’s amplitude?
The amplitude of a wave is its maximum displacement from its equilibrium position
What is a wave’s frequency?
The number of complete waves that pass a point per second
What is the period of a wave?
THe length of time taken for one complete wave to pass a given point
How are frequency and period linked?
f = 1/T
What is wavelength?
Distance between the same point on 2 adjacent waves
What is the equation for wave speed?
v = fλ
Describe a longitudinal wave
Particle oscillations are parallel to direction of the wave’s motion
Consists of rarefactions (low pressure regions), and compressions (high pressure regions)
Describe a transverse wave
Particles oscillations are perpendicular to the wave’s motion
Consists of peaks (max positive displacement) and troughs (max negative displacement)
What is a progressive wave
A wave that transfers energy from one point to another without any transfer of matter
What is a standing wave
A wave that stores energy instead of transferring it from one place to another
What is path difference a measure of
How far ahead one wave is compared to another
What is a wave’s phase
A measure of how far through its cycle the wave is. Usually measured in radians 1 cycle = 2π
What is the phase difference between 2 waves at a given point
The difference between 2 waves at a given point
What happens when 2 waves meet
Interference occurs
What happens when 2 waves meet in phase
They will interfere and undergo constructive interference
What happens when 2 waves meet in antiphase
They will interference and undergo destructive interference
How is a standing wave formed on a string
A wave reflects from a closed end meaning 2 identical waves are travelling in opposite directions down the same string
At points where the waves meet in phase, constructive interference occurs and an antinode is formed
At points where waves meet in antiphase, destructive interference occurs and a node is formed
What is a node
A point of minimum displacement
What is an antinode
A point of maximum displacement
What factors does the speed of a transverse wave on a string depend on
Time period
Mass per unit length of string
State the equation used to calculate speed of transverse wave on a string
v^2 = T/μ
What is the equation used to calculate intensity
I = P/A
What is the refractive index of a material through which light travels a speed of ‘v’
n = c/v
State the equation linking refractive indexes and angles at an interface in 2 different mediums
n1 sinθ1 = n2 sinθ2