Topic 5: Waves Flashcards
what is phase difference
The amount one wave lags behind another
What is phase
A measure of a position of a certain point along a wave
(phase diff also counts as the distance between these points)
What is a transverse wave
A wave in which the vibrations are perpendicular to the direction of travel
What is a longitudinal wave
A wave in which vibrations are parallel to the direction of travel.
What is amplitude
The Maximum Magnitude of displacement
what is wavelength
The length of one whole wave cycle. e.g crest to crest or trough to trough.
What is displacement
How far a point on a wave has moved from its undisturbed position
what is the speed of light in air
3x10-8
What is the Frequency
The number of cycles (vibrations)per second passing a given point
What is the Unit and symbol for frequency
Hz
F
What is the unit and symbol for wave speed
Ms^-1
V
What is the unit and symbol for a Period
s T
What is the unit and symbol for Wavelength
Meters
λ
What is the Equation for Wave speed
V=f x λ
Give 6 features of a wave
Absorption, Transmission,Reflection, Refraction,Interference,Diffraction
Which two features of a wave provide evidence for the existence of Waves
Diffraction & Interference
What is absorption
when energy is absorbed by an object
Whats is transmission
when energy is transmitted from one source to another
What is reflection
When a wave bounces of a surface
What is refraction
When a Wave changes speed Because is enters a new medium
What is interference
When 2 waves meet at the same point and adds displacement
What is diffraction
When Waves spread Through a Gap
Define intensity
How much energy a wave is carrying
Define Superposition
When two or more waves pass through each other. The displacement of this overlap is the vector sum of two waves
What is A Wave
When the vibration of a medium Travels but the medium itself Does not Travel
Name the waves in the Electromagnetic spectrum in order of rising frequency falling wavelength.
radio waves, microwaves, infrared light, visible light, ultraviolet light, X-rays, and gamma rays.
What type of wave are the waves in the electromagnetic spectrum.
Transverse waves
What is total constructive interference
when two waves interfere they are amplified.
where the path difference is a whole number due to the waves arriving in phase
What is total destructive interference
when two waves interfere they are diminished .
Define coherent
Sources that have the same wavelength and frequency and a fixed phase difference between them
What is the maximum point in total constructive interference
The brightest point
What is the minimum point in total Destructive interference
The darkest point
What is the Equation for total Constructive interference
nλ
What is the Equation for total Destructive interference
n+1/2 λ
What is compression
Areas of High pressure in a longitudinal wave
What is rarefaction
Areas of low pressure in a longitudinal wave
How do you calculate the wavelength in a longitudinal wave
By finding the distance from either compression to compression of rarefaction to rarefacation
What is the equation for phase difference
θ=2πx/λ
what unit are we referring to when we talk about wave path
lander
what unit are we referring to when we talk about wave Difference
pi
Define a progressive wave
An oscillation that travels through matter transferring energy from one place to another but not transferring matter.
Define a stationary wave
When to waves travelling in opposite directions waves reflects before they superimpose.
Define a Node
When amplitude is equal to zero
Define an Anti node
When amplitude is at the maximum
What is the diffraction equation
d \sin \theta=n \lambda
what is the pulse echo technique
A diagnostic technique that uses a short duration ultrasound pulses, transmitted to a place of interest causing echo signals which are detected and displayed.
what is the pulse echo distance equation
X=Vt/2
How is an image constructed using pulse echo
Using the energy transmitted back to the transducer
What is the amount of energy refracted & transmitted dependent on
Density
What sends out pulse in the ultrasound example
A Transducer
What is the equation for fringe width
W= λD/s
w= fringe width
s= distance between slits
D=distance between slits and screen
λ=wavelength
