Week 8 Term 3 2024 Doppler Effect, Beats, Two Point Source & Multi point Source Interference

 Homework

• Act 4A, p.56 Properties of Waves
• Act 5A, p.73-74 Standing Waves
• Act 5B, p.79-80 Music
• Ex 3D, p.75-79, Standing Waves and Music
• Act 6A, p.85-86 The Doppler Effect
• Ex 3E, p.81-84, Beats
• Ex 3A, p. 50-53 Basic Wave Properties
• Ex 3B, p. 57-63 Two Point Source Interference
• Ex 3C, p. 66-70 Multi Point Source Interference

Doppler Effect

The Doppler Effect: what does motion do to waves?

Doppler Effect

Intro to the Doppler Effect

Doppler Effect Observed Frequency Equation

Sonic Boom

Doppler Shifting Song

Beats

two waves of a similar frequency (similar wavelength) superimpose to come in and out of phase causing constructive and deconstructive interference respectively. This causes a warbling/beat sound of frequency (fb) equal to the difference in respective frequencies

fb = | f1 - f2 |

Wave Beats

Easy Beats- Physics

Wine Glass Resonance in Slow Motion

Two Point Source Interference

n𝜆 = dsin(𝛳)

Double Slit App - Physics Classroom

Wave-Particle Duality Applied to the Double Slit Experiment

Diffraction Grating of White Light 

(Multi-Point Source Interference)

Green vs White Light Diffraction

Multiple Point Source Interference

Multiple Point Source Interference

Thin Film Interference

Thin Film Interference

Making Colour with Holes

Why Blue is so rare

Visible Spectrum

Week 7 Term 3 2024 Standing Waves

  Homework

• Act 4A, p.56 Properties of Waves
• Act 5A, p.73-74 Standing Waves
• Act 5B, p.79-80 Music

• Ex 3D, p.75-79, Standing Waves and Music

Longitudinal Waves

Particle displacement in the medium is parallel to the direction of wave propagation e.g. sound waves, primary earthquake waves



Transverse Waves
Particle displacement in the medium is perpendicular to the direction of wave propagation e.g. light and other electromagnetic waves, secondary earthquake waves





Ocean Waves



Surface Waves



Frequency - Period


Sound Waves
Superposition of Waves


Waves travel through each other and the total amplitude at any moment is equal to the sum of amplitudes of the individual waves.





Standing Waves
In musical instruments - when a reflected wave travels back through itself causing fixed points of Nodes (Deconstructive Interference) and Antinodes (Constructive Interference) due to the fractional relationship between the wavelength (𝜆) of the wave and the length (L) of the resonating chamber

in musical instruments - when a reflected wave travels back through itself causing fixed points of Nodes (Deconstructive Interference) and Antinodes (Constructive Interference) due to the fractional relationship between the wavelength (𝜆) of the wave and the length (L) of the resonating chamber


Harmonic	String	Double Open Ended Pipe	Closed Ended Pipe
1st	𝜆 = 2L f = f1st	𝜆 = 2L f = f1st	𝜆 = 4L f = f1st
2nd	𝜆 = L f = 2f1st	𝜆 = L f = 2f1st
3rd	𝜆 = ⅔ L f = 3f1st	𝜆 = ⅔ L f = 3f1st	𝜆 = 4/3 L f = 3f1st
4th	𝜆 = ½ L f = 4f1st	𝜆 = ½ L f = 4f1st
5th	𝜆 = ⅖ L f = 5f1st	𝜆 = ⅖ L f = 5f1st	𝜆 = ⅘ L f = 5f1st
Table of Musical Notes and Frequencies


Standing Waves Part I: Demonstration


Standing Waves Part II: Explanation


Standing Waves




Standing Waves on a String



1st Harmonic	2nd Harmonic	3rd Harmonic	4th Harmonic
𝜆 = 2L	𝜆 = L	𝜆 = ⅔ L	𝜆 = ½ L
f = f1st	f = 2f1st	f = 3f1st	f = 4f1st



Standing Waves in a Pipe






Standing Waves in a Wave Tank




Standing Waves on a 2D Plate


Cymatics


   Acoustic Levitation in ULTRA SLOW MOTION
Inside The Navy's Indoor Ocean
Timbre









Timbre is caused by the shape of the repeating wave unit. This gives instruments their characteristic sound even when playing the same note



 Musical Notes and Frequencies

("Middle C" is C₄ )

Note	Frequency (Hz)	Wavelength (cm)
C0	16.35	2109.89
C#0/Db0	17.32	1991.47
D0	18.35	1879.69
D#0/Eb0	19.45	1774.20
E0	20.60	1674.62
F0	21.83	1580.63
F#0/Gb0	23.12	1491.91
G0	24.50	1408.18
G#0/Ab0	25.96	1329.14
A0	27.50	1254.55
A#0/Bb0	29.14	1184.13
B0	30.87	1117.67
C1	32.70	1054.94
C#1/Db1	34.65	995.73
D1	36.71	939.85
D#1/Eb1	38.89	887.10
E1	41.20	837.31
F1	43.65	790.31
F#1/Gb1	46.25	745.96
G1	49.00	704.09
G#1/Ab1	51.91	664.57
A1	55.00	627.27
A#1/Bb1	58.27	592.07
B1	61.74	558.84
C2	65.41	527.47
C#2/Db2	69.30	497.87
D2	73.42	469.92
D#2/Eb2	77.78	443.55
E2	82.41	418.65
F2	87.31	395.16
F#2/Gb2	92.50	372.98
G2	98.00	352.04
G#2/Ab2	103.83	332.29
A2	110.00	313.64
A#2/Bb2	116.54	296.03
B2	123.47	279.42
C3	130.81	263.74
C#3/Db3	138.59	248.93
D3	146.83	234.96
D#3/Eb3	155.56	221.77
E3	164.81	209.33
F3	174.61	197.58
F#3/Gb3	185.00	186.49
G3	196.00	176.02
G#3/Ab3	207.65	166.14
A3	220.00	156.82
A#3/Bb3	233.08	148.02
B3	246.94	139.71
C4	261.63	131.87
C#4/Db4	277.18	124.47
D4	293.66	117.48
D#4/Eb4	311.13	110.89
E4	329.63	104.66
F4	349.23	98.79
F#4/Gb4	369.99	93.24
G4	392.00	88.01
G#4/Ab4	415.30	83.07
A4	440.00	78.41
A#4/Bb4	466.16	74.01
B4	493.88	69.85
C5	523.25	65.93
C#5/Db5	554.37	62.23
D5	587.33	58.74
D#5/Eb5	622.25	55.44
E5	659.25	52.33
F5	698.46	49.39
F#5/Gb5	739.99	46.62
G5	783.99	44.01
G#5/Ab5	830.61	41.54
A5	880.00	39.20
A#5/Bb5	932.33	37.00
B5	987.77	34.93
C6	1046.50	32.97
C#6/Db6	1108.73	31.12
D6	1174.66	29.37
D#6/Eb6	1244.51	27.72
E6	1318.51	26.17
F6	1396.91	24.70
F#6/Gb6	1479.98	23.31
G6	1567.98	22.00
G#6/Ab6	1661.22	20.77
A6	1760.00	19.60
A#6/Bb6	1864.66	18.50
B6	1975.53	17.46
C7	2093.00	16.48
C#7/Db7	2217.46	15.56
D7	2349.32	14.69
D#7/Eb7	2489.02	13.86
E7	2637.02	13.08
F7	2793.83	12.35
F#7/Gb7	2959.96	11.66
G7	3135.96	11.00
G#7/Ab7	3322.44	10.38
A7	3520.00	9.80
A#7/Bb7	3729.31	9.25
B7	3951.07	8.73
C8	4186.01	8.24
C#8/Db8	4434.92	7.78
D8	4698.63	7.34
D#8/Eb8	4978.03	6.93
E8	5274.04	6.54
F8	5587.65	6.17
F#8/Gb8	5919.91	5.83
G8	6271.93	5.50
G#8/Ab8	6644.88	5.19
A8	7040.00	4.90
A#8/Bb8	7458.62	4.63
B8	7902.13	4.37