Topic 2 - Waves Flashcards
What is a pulse?
A single wave
What is the amplitude of a wave?
The distance from the median line and the crest/trough of the wave
What is a pulse?
A single wave
What is amplitude?
The distance from the middle of the wave to the crest/trough
What is the wavelength?
Distance to complete 1 repetition
T or F: λ represents wavelength?
True
T or F: Frequency is the amount of seconds it takes for 1 repetition?
False
What is the unit for frequency?
Hertz
What is frequency?
The number of waves per second
T or F: Period is the time taken for 1 repetition?
True
What is the symbol for period?
T
What is the equation for period?
T = 1/F
How do you find the speed of a wave?
V = F(frequency) x λ (wavelength)
T or F: Intensity is the same as impulse?
False
What is the equation for Intensity?
I = W / r(distance)^2
What does intensity measure?
Power over area
What is the distance between transverse and longitudinal waves?
Transverse are an object moving, longitudinal are compressions of air.
T or F: Talking uses longitudinal waves?
True
When a rope/wave is fixed to a wall, what will the wave do when it hits the wall?
Reflect
T or F: A wave will stay the same when hitting a wall without being secured?
True
If a rope changes from light to heavy, will any of the wave be reflected?
Yes
If a heavy rope changes from heavy to light, what will the velocity do?
Increase
What is the law of reflection?
I (incidence) = R (reflection)
What is refraction?
The lengthening /shortening of wavelengths based on medians
If a wave travels into a denser medium, will the wavelengths increase or decrease?
Decrease
T or F: A wave passing passes into a lighter median, it will refract toward the normal?
False
What is diffraction?
spreading of waves through gaps
If a wavelength is equal to a gap, will it diffract?
Yes
T of F: A gap bigger than the wavelength will result in large diffraction
False
What is the difference between constructive and destructive superposition?
Constructive is 2 waves on the same plane resulting in a larger wave, destructive is 2 waves on different planes resulting in smaller or no waves
What is the equation for destructive superposition?
(n + 0.5) x λ
T or F: Nλ tells if the superposition will be constructive
True
What is an antinode?
The extreme points of a wave
T or F: A node is the middle points of a wave?
True
What is the fundamental frequency?
the smallest frequency
What is the equation for wavelengths with pipes/strings closed at both ends?
λ = (2 x L) / n
What does n stand for in λ = (2 x L) / n
Number of harmonics/frequencies
How do you find frequency for a string/pipe fixed at both ends?
F = (n x V) / (2 x L)
How do you calculate the frequency of light?
F = C / λ
What does c mean in light?
Speed of light
What is the speed of light?
~ 3 x 10^8
What is the visible range for light in frequencies?
400 x 10^12 - 800 x 10^12
T or F: A light wave with wavelength 800nm could be seen by the human eye?
False
What is the visible range of light with wavelengths?
790nm - 390nm
How many lines do you draw to create a ray diagram?
2
Where do the 2 lines go for a ray diagram?
1 perpendicular to the object until it touches the mirror/lense, 2 straight through the focal point then perpendicular to mirror/lense
How far is the focal point?
0.5 x Centre
How can you find the refractive index?
Sin i / sin r = v1 / v2 = λ1 / λ2 = n2 / n1 = index
What does the critical angle indicate?
Total internal reflection
What is the equation for the critical angle?
Sin (ic) = n2/n1
