1. Why Can’t we see Sounds?

2. By applying  the mathematical formula SWBAT to evaluate the frequency, wavelength, and speed of waves traveling in various media using the following equations :
T = 1/f f=1/T V= λf
Performance Expectations :
I can use mathematical representations to support a claim regarding relationships among the frequency, wavelength and the speed of waves traveling in various media . T = 1/f f=1/T V= λf
Learning Targets :
I can analyze and describe the motion of mechanical waves through various media using a Pendulum and Spring Mass Systems . I will be able to know the effect of the length of the pendulum and mass on springs to its vibration measured by the system’s period and frequency.

3. WAVES
SIMPLE HARMONIC MOTION
PROPERTIES OF WAVES
WAVE INTERFERENCE
SOUND WAVES

4. Telephone TEST Design An Experiment
Purpose :
What is the correlation of length of string to speed of sound and clarity of sound?
What is the correlation of type of materials to speed of sound and clarity of sound ?
Materials :
6 sets of can telephone
strings of different length ( 2.5m. 5m, 10m)
2.5 m yarn
2.5 m copper wire
2.5 m aluminum wire
meter stick
stop watch

5. Diagram:
Measurement :
length of the transmission line
elapsed time of transmission- average time
speed of sound
clarity of sound ( 3- clear , 2- sounds like, 1 unclear, 0- no sound)- average clarity
Equation :
average time
speed
average clarity

6. Errors :
time measurement
volume of sound
length of words – the same length of words for each telephone
stretch enough the line
Graphs :
4 graphs : speed VS length of string- line graph /linear equation
speed VS type of materials – bar graph
clarity VS type of materials – bar graph
clarity VS length of string – line graph/ Linear equation

7. Post Lab Discussion 1. What is the fastest speed recorded?
2.What is the best length of string that provides the fastest speed?
3.What is the best clarity ave of sound recorded?
4.What is the best length of string that provides the best clarity ave?
5.What is 2.5 m material provides the fastest speed?
6.What 2.5 m material provides the best clarity ?
7.What is the mathematical correlation of length to the speed of sound and length to the clarity of sound ?
8.What are some sources of errors?
9. What will be your recommendation / suggestions in the future in doing this experiment again ?
10.How does sound transmits ?

8. Notes: Vibrations, Waves,Oscillations,Sounds, Electromagnetic Waves, Light

9. SOUND Discussion College Physics ; Chapter 14 p 478-482
14.1 – X partner p
14.2 – Y Partner p
Sound PPT

10. P 496-498 College Physics Definition of Doppler Effect 4 Equations :
f equation when the source moves towards the listener
f equation when the source moves away from the listener
f equation when the listener moves toward the stationary source
f equation when the listener moves away from the source

11. Pendulum Motion Packet
Groups of 4
Force Analysis Of Pendulum
Sinusoidal Nature of a Pendulum
Energy analysis
Period of A Pendulum
Read your topic – 20 minutes
Take Notes
Go around and Share your information – 5minutes /each person .
Write and number all the information about pendulum regarding all subtopic on paper . Score it.

12. SIMPLE HARMONIC MOTION
Simple pendulum
For small angles
Restoring force is proportional to x.
Work done is ZERO
Max PE at the highest point
Max KE at the lowest point
Period of a pendulum
T = 2 √ l/g
Units: sec/cycle or sec/revolution or sec

13. SIMPLE HARMONIC MOTION

14. SIMPLE HARMONIC MOTION

15. Pendulum Experiment Purpose :
To determine the effect of the length of string to frequency
To determine the effect of the mass of the bob to frequency
Materials :
Iron stand , Iron ring , long string ,medium length string , short string , meter stick , washers, stopwatch , calculator , paper clip

16. Diagram Measurements String Length, m Number of washers Time= 10sec
Amount
Frequency experimental , hertz
Period experimental , sec
Period calculated, sec
% error
Frequency calculated, hertz

17. Equations :
Frequency = Cycles Revolutions/ time
Period T = 1/ frequency
Period (T) = 2Π√l/g
Frequency (f) = 1/period (T)
% error = |Experimental - Calculated|
______________________ X 100
Calculated

18. Errors :
Part 2 : Measurement:
Use the Long string .
Number of Washers
Length, m
Time, sec
Amount Cycles
Frequency experimental (f), Hertz
Period experimental (T), sec

19. Post Lab Discussions: Part 1:
1.What was your highest frequency ? Lowest frequency ?
2. What length of string provided the highest frequency? Lowest frequency?
3. What is the correlation of frequency and period?
4. How would you explain period and frequency in your own words?
5. What was your highest % error?
6. What do your think are the sources of error in this experiment ?
7. How did you control the sources of error?
8. Does the length of the string affect the frequency ?
9. What should you do with the string length to produce high frequency ? Low frequency ?

20. Part 2:
1.What was your highest frequency ? Lowest frequency ?
2. What amount of washers provided the highest frequency? Lowest frequency?
3. Was the frequency affected by increasing the number of washers?

21. Spring Motion Packet Groups of 5 a. Hooke’s Law
Force Analysis Of Spring
Sinusoidal Nature of a Spring
Energy analysis
Period of A Spring
Read your topic – 15 minutes
Take Notes
Share your information – 5minutes /each person .
Write and number all the information about pendulum regarding all subtopic on paper . Score it.

22. Spring Experiment Purpose :
To determine the relation of the Force (Fs) on the stretch length (x) of the spring.
To calculate the Spring constant .
To calculate the period and frequency of the spring using T = 2Π m/k
Materials :
Springs , 10 g , 2- 20g, 50g
Background Information and Physics Concepts
2 paragraphs about Springs
IV. Diagram Set Up – Draw and label the experiment set up

24. SIMPLE HARMONIC MOTION
Motion that is repeating or periodic.
Two types
Spring
Hooke’s Law states that the restoring force is proportional to the displacement
F = -kx
Units: Newtons
Negative: direction of the Force is opposite the displacement.

25. SIMPLE HARMONIC MOTION

26. SIMPLE HARMONIC MOTION

27. SIMPLE HARMONIC MOTION
Stretch or compression provides three types of energy.
Max displacement
EPE = ½ k x 2
V = 0
A increase to max
Equilibrium position
Min x
Max KE
Max velocity
a = 0

28. SIMPLE HARMONIC MOTION
Horizontal springs:
EPE elastic KE
Vertical springs:
PE gravitational
Conservation of energy applies
Friction or damping force

29. SIMPLE HARMONIC MOTION
Period of a spring
T = 2 √ m/k
Units: sec/cycle or sec/revolution or sec
f = 1 / T
Units: cycle/sec or revolution/sec or Hertz or s-1

30. SIMPLE HARMONIC MOTION

31. Initial Conditions and Equations of Motion
P 455 College Physics – Buffa

32. CW: Problems P
2,3,4,10,11,12,13,14,16a-b,20,21,32,33,34,35,,38,39,44,47,49

33. PROPERTIES OF WAVES Follows a simple harmonic motion Needs a source
Medium = matter
Matter does NOT travel only energy
Mechanical waves need a medium to travel
EM does not need a medium to travel
Pulse: single wave

34. CW : Two Types of Waves Venn Diagram
Compare and Contrast Transverse Waves and Longitudinal Waves
Definition
Synonym
Example
Drawing

35. PROPERTIES OF WAVES Two types of waves Transverse waves
Disturbance is perpendicular to the propagation EM

36. Longitudinal or compressional waves
PROPERTIES OF WAVES
Longitudinal or compressional waves
Disturbance is parallel to the propagation
Sound waves

37. PROPERTIES OF WAVES Parts of the wave
Wavelength (): length of a wave measured between two consecutive identical points
Frequency (f)
Period (T)
Amplitude (A): max height of the wave

38. PROPERTIES OF WAVES Crest: highest point of transverse wave
Trough: lowest point of transverse wave

39. PROPERTIES OF WAVES

40. PROPERTIES OF WAVES
Compression: high density portion of compressional wave
Rarefaction: low density portion of compressional wave

41. PROPERTIES OF WAVES

42. Wave Equation Speed = frequency x wavelength c = f  v = f 
c = speed of light = 3.0 x 10 8 m/s

43. 25.4 Wave Speed
You can calculate the speed of a wave by multiplying the wavelength by the frequency.

44. 25.4 Wave Speed
The speed of a wave depends on the medium through which the wave moves.
Whatever the medium, the speed, wavelength, and frequency of the wave are related.

45. 25.4 Wave Speed
If the wavelength is 1 meter, and one wavelength per second passes the pole, then the speed of the wave is 1 m/s.

46. where v is wave speed,  is wavelength, and f is wave frequency.
If the wavelength is 3 meters and if two crests pass a stationary point each second, then 3 meters × 2 waves pass by in 1 second.
The waves therefore move at 6 meters per second.
v = f
where v is wave speed,  is wavelength, and f is wave frequency.

47. 25.4 Wave Speed
In air, the product of wavelength and frequency is the same for every frequency of sound.
That’s why you don’t hear the high notes in a chord before you hear the low notes. The sounds all reach you at the same time.
Long wavelengths have low frequencies, and short wavelengths have high frequencies.

48. 25.4 27. Wave Speed 2.13 340 264 0.86 396 0.64 Wavelength m Frequency
Wavelength and frequency vary inversely to produce the same wave speed for all sounds.
Wavelength m
Frequency Hz
Wave Speed
m/s
2.13
340
264
0.86
396
0.64

49. CW : V=λf

50. CW:Problems
63-70 p

51. Reading CW – 50 pts Properties of the Wave Wave Characteristics
Rule :3 sentences , drawing , example + equation
Assign One Research Topic
10 minutes – Find the answer from
College Physics by Buffa
Close the book.
Interact with classmates- exchange research infromation to classmates vocally .( 2 minutes /question) – 5 points each research information
Line up – face to face (Birthdate) . Points will be taken off if classmates were allowed to just copy from paper without explanation.

52. Reading Wave Properties p 460 - 467

53. CW : Wave Properties 76, 78,80,82,86,88,89,90,92 Homework :
77,79,83,89,91,93

54. WAVE INTERFERENCE Energy travels…NOT matter
Superposition Principle: two or more waves will combine algebraically
Waves pass through without altering their shapes and size.

55. WAVE INTERFERENCE Constructive: resulting wave is larger in amplitude
In phase

56. WAVE INTERFERENCE Destructive: resulting wave is smaller in amplitude
Out of phase

57. WAVE INTERFERENCE

58. WAVE INTERFERENCE

59. WAVE INTERFERENCE

60. WAVE BEHAVIOR
Determining behavior when wave reaches a boundary (interface between two medium)
Incident pulse: incoming wave
Reflected pulse: a wave bouncing off a boundary
Transmitted pulse: wave continuing through to next medium
Upright
Inverted

61. WAVE BEHAVIOR Reflection: wave hits a boundary and returns
Newton’s third law
Speed and wavelength are the same
Amplitude is smaller

62. WAVE BEHAVIOR

63. WAVE BEHAVIOR
Transmitted: slower than reflected and smaller wavelength
Reflected: speed and wavelength are same as incident

64. WAVE BEHAVIOR Transmitted: faster and larger wavelength
Reflected: same speed and wavelength as incident

65. WAVE BEHAVIOR
Refraction: change in direction of waves traveling from one medium to another
Speed and wavelength changes

66. WAVE BEHAVIOR
Diffraction: change in direction of waves as the wave passes through opening or around a barrier.

67. SOUND WAVES Compressional or longitudinal wave
High pressure and low pressure region
Speed depends on medium
vsolid > vliquid> vgas
Speed depends on temperature
Direct relationship
343 m/s at room temperature

68. SOUND WAVES

69. SOUND WAVES

70. SOUND WAVES Range of sound 20 to 20000 Hz
Infrasonic, audible, ultrasonic
Measured in decibels
Loudness is not intensity but related to amplitude of the wave
Energy of the wave is proportional to A2
Intensity is power / area

71. STANDING WAVES
Standing waves: reflected and incident wave interact to appear to be standing
Antinodes: largest amplitude
Nodes: zero amplitude

72. STANDING WAVES

73. STANDING WAVES
L =  /2
L = 2 / 2 = 
L = 3 / 2
L = 4 / 2 = 2

74. STANDING WAVES Increases by increments of  /2
Longest wavelength: L = n /2
where n = 1, 2, 3, 4……
Fundamental frequency: lowest frequency
v = f 
f = v /  = nv / 2L
Harmonics: multiples of the fundamental frequency

75. OPEN PIPES
L =  /2
L = 2 / 2 = 
L = 3 / 2
L = 4 / 2 = 2

76. OPEN PIPES Increases by increments of  /2
Longest wavelength: L = n /2
where n = 1, 2, 3, 4……
Fundamental frequency: lowest frequency
v = f 
f = v /  = nv / 2L

77. CLOSED PIPES
L =  /4
L = 3 / 4
L = 5 / 4
L = 7 / 4

78. CLOSED PIPES Increases by increments of  /2
Longest wavelength: L = n /4
where n = 1, 3, 5……
Fundamental frequency: lowest frequency
v = f 
f = v /  = nv / 4L

79. Group Report – open score Use Internet websites; College Physics; Conceptual Physics
1. Doppler Effect
2. Bow Waves
3. Shock Waves
4. Resonance
5. Beats
# of information, +2 , +5,+10 ( loudness)

80. DOPPLER EFFECT Approaching Wavelength decreases Speed constant
Frequency increases
Pitch = frequency
Leaving
Wavelength increases
Speed constant
Frequency decreases

81. DOPPLER EFFECT Determine the movement of Stars and Planets Blue Shift
wavelength decreases
frequency increases
approaching
Red Shift
wavelength increases
frequency decreases
leaving

82. DOPPLER EFFECT

83. BOW/SHOCK WAVES
Bow waves: waves overlap at the edges and the pattern made by the overlapping waves is a V shape; 2-D
Shock waves: 3-D
Sonic boom: sharp crack heard when the object breaks the overlapping waves barrier

84. BOW/SHOCK WAVES
V of object < V of wave

85. BOW/SHOCK WAVES
V of object = V of wave
V of object > V of wave

86. RESONANCE
Natural frequency: frequency in which an object vibrates when hit
Resonance: vibrating object matches the natural frequency of an object and increasing the amplitude

87. RESONANCE

88. BEATS
Two or more sounds wave interfere constructively or destructively producing sound as beats
Beats = |f1 – f2|

90. 25.9 The Doppler Effect
As a wave source approaches, an observer encounters waves with a higher frequency. As the wave source moves away, an observer encounters waves with a lower frequency.

91. 25.9 The Doppler Effect
Imagine a bug jiggling its legs and bobbing up and down in the middle of a quiet puddle.
The crests of the wave it makes are concentric circles, because the wave speed is the same in all directions.
If the bug bobs in the water at a constant frequency, the wavelength will be the same for all successive waves.
The wave frequency is the same as the bug’s bobbing frequency.

92. 25.9 The Doppler Effect
Suppose the jiggling bug moves across the water at a speed that is less than the wave speed.
The wave pattern is distorted and is no longer concentric.
The center of the outer crest is made when the bug is at the center of that circle.
The center of the next smaller crest was made when the bug was at the center of that circle, and so forth.

93. 25.9 The Doppler Effect
The bug maintains the same bobbing frequency as before.
However, an observer would encounter a higher frequency if the bug is moving toward the observer.
This is because each successive crest has a shorter distance to travel so they arrive more frequently.

94. 25.9 The Doppler Effect
If the bug is moving away from the observer, on the other hand, there is a lower frequency.
There is a longer time between wave-crest arrivals.
Each crest has to travel farther than the one ahead of it due to the bug’s motion.

95. 25.9 The Doppler Effect
This apparent change in frequency due to the motion of the source (or receiver) is called the Doppler effect.
The greater the speed of the source, the greater will be the Doppler effect.

96. 25.9 The Doppler Effect Sound
The Doppler effect causes the changing pitch of a siren.
When a firetruck approaches, the pitch sounds higher than normal because the sound wave crests arrive more frequently.
When the firetruck passes and moves away, you hear a drop in pitch because the wave crests are arriving less frequently.

97. 25.9 The Doppler Effect
Police use the Doppler effect of radar waves to measure the speeds of cars on the highway.
Radar waves are electromagnetic waves.
Police bounce them off moving cars. A computer built into the radar system compares the frequency of the radar with the frequency of the reflected waves to find the speed of the car.

98. 25.9 The Doppler Effect Light
The Doppler effect also occurs for light.
When a light source approaches, there is an increase in its measured frequency.
When it recedes, there is a decrease in its frequency.

99. 25.9 The Doppler Effect
Increasing frequency is called a blue shift, because the increase is toward the high-frequency, or blue, end of the spectrum.
Decreasing frequency is called a red shift, referring to the low-frequency, or red, end of the color spectrum.
Distant galaxies show a red shift in their light. A measurement of this shift enables astronomers to calculate their speeds of recession.

100. 25.9 The Doppler Effect think!
When a source moves toward you, do you measure an increase or decrease in wave speed?

101. 25.9 The Doppler Effect think!
When a source moves toward you, do you measure an increase or decrease in wave speed?
Answer:
Neither! It is the frequency of a wave that undergoes a change, not the wave speed.

102. 25.9 The Doppler Effect
How does the apparent frequency of waves change as a wave source moves?

103. 25.10 Bow Waves
A bow wave occurs when a wave source moves faster than the waves it produces.

104. 25.10 Bow Waves
When the speed of the source in a medium is as great as the speed of the waves it produces, something interesting happens.
The waves pile up.
If the bug swims as fast as the wave speed, it will keep up with the wave crests it produces.
The bug moves right along with the leading edge of the waves it is producing.

105. 25.10 Bow Waves
The same thing happens when an aircraft travels at the speed of sound.
The overlapping wave crests disrupt the flow of air over the wings, so that it is harder to control the plane when it is flying close to the speed of sound.

106. 25.10 Bow Waves
When the plane travels faster than sound, it is supersonic.
A supersonic airplane flies into smooth, undisturbed air because no sound wave can propagate out in front of it.
Similarly, a bug swimming faster than the speed of water waves is always entering into water with a smooth, unrippled surface.

107. 25.10 Bow Waves
When the bug swims faster than wave speed, it outruns the wave crests it produces.
The crests overlap at the edges, and the pattern made by these overlapping crests is a V shape, called a bow wave.
The bow wave appears to be dragging behind the bug.
The familiar bow wave generated by a speedboat is produced by the overlapping of many circular wave crests.

108. 25.10 Bow Waves v= speed of bug vw= wave speed
The wave patterns made by a bug swimming at successively greater speeds change. Overlapping at the edges occurs only when the source travels faster than wave speed.

109. 25.10 Bow Waves
What causes a bow wave?

110. 25.11 Shock Waves
A shock wave occurs when an object moves faster than the speed of sound.

111. 25.11 Shock Waves
A speedboat knifing through the water generates a two-dimensional bow wave.
A supersonic aircraft similarly generates a shock wave.
A shock wave is a three-dimensional wave that consists of overlapping spheres that form a cone.
The conical shock wave generated by a supersonic craft spreads until it reaches the ground.

112. 25.11 Shock Waves
The bow wave of a speedboat that passes by can splash and douse you if you are at the water’s edge.
In a sense, you can say that you are hit by a “water boom.”
In the same way, a conical shell of compressed air sweeps behind a supersonic aircraft.
The sharp crack heard when the shock wave that sweeps behind a supersonic aircraft reaches the listeners is called a sonic boom.

113. 25.11 Shock Waves We don’t hear a sonic boom from a subsonic aircraft.
The sound wave crests reach our ears one at a time and are perceived as a continuous tone.
Only when the craft moves faster than sound do the crests overlap and encounter the listener in a single burst.
Ears cannot distinguish between the high pressure from an explosion and the pressure from many overlapping wave crests.

114. 25.11 Shock Waves
A common misconception is that sonic booms are produced only at the moment that the aircraft surpasses the speed of sound.
In fact, a shock wave and its resulting sonic boom are swept continuously behind an aircraft traveling faster than sound.

115. 25.11 Shock Waves
The shock wave has not yet encountered listener C, but is now encountering listener B, and has already passed listener A.

116. 25.11 Shock Waves
A supersonic bullet passing overhead produces a crack, which is a small sonic boom.
When a lion tamer cracks a circus whip, the cracking sound is actually a sonic boom produced by the tip of the whip.
Snap a towel and the end can exceed the speed of sound and produce a mini sonic boom.
The bullet, whip, and towel are not in themselves sound sources. When they travel at supersonic speeds, sound is generated as waves of air at the sides of the moving objects.

117. 25.11 Shock Waves
What causes a shock wave?

118. A,b,c,d letters

119. Assessment Questions
The time it takes for a pendulum to swing to and fro is considered its
frequency.
period.
wavelength.
amplitude.

120. Assessment Questions
The time it takes for a pendulum to swing to and fro is considered its
frequency.
period.
wavelength.
amplitude.
Answer: B

121. Assessment Questions The frequency of a wave is the inverse of its
period.
wavelength.
amplitude.

122. Assessment Questions The frequency of a wave is the inverse of its
period.
wavelength.
amplitude.
Answer: B

123. Assessment Questions A wave transfers amplitude. wavelength.
frequency.
energy.

124. Assessment Questions A wave transfers amplitude. wavelength.
frequency.
energy.
Answer: D

125. Assessment Questions
The speed of a wave can be found by multiplying its frequency by the
period.
wavelength.
amplitude.
density of the medium that carries the wave.

126. Assessment Questions
The speed of a wave can be found by multiplying its frequency by the
period.
wavelength.
amplitude.
density of the medium that carries the wave.
Answer: B

127. Assessment Questions
The vibrations along a transverse wave move in a direction
along the wave in the same direction.
perpendicular to the wave.
parallel to the wave.
along the wave in the opposite direction.

128. Assessment Questions
The vibrations along a transverse wave move in a direction
along the wave in the same direction.
perpendicular to the wave.
parallel to the wave.
along the wave in the opposite direction.
Answer: B

129. Assessment Questions
The vibrations along a longitudinal wave move in a direction
along and parallel to the wave.
perpendicular to the wave.
below the wave.
above the wave.

130. Assessment Questions
The vibrations along a longitudinal wave move in a direction
along and parallel to the wave.
perpendicular to the wave.
below the wave.
above the wave.
Answer: A

131. Assessment Questions Interference is characteristic of
only sound waves.
only light waves.
only water waves.
all waves.

132. Assessment Questions Interference is characteristic of
only sound waves.
only light waves.
only water waves.
all waves.
Answer: D

133. Assessment Questions Standing waves appear to be constantly moving.
are the result of waves overlapping in phase and out of phase.
form only in multiples of three.
do not increase with increasing frequency.

134. Assessment Questions Standing waves appear to be constantly moving.
are the result of waves overlapping in phase and out of phase.
form only in multiples of three.
do not increase with increasing frequency.
Answer: B

135. Assessment Questions The Doppler effect changes the
frequency due to motion.
speed of sound due to motion.
speed of light due to motion.
radar waves in a police car.

136. Assessment Questions The Doppler effect changes the
frequency due to motion.
speed of sound due to motion.
speed of light due to motion.
radar waves in a police car.
Answer: A

137. Assessment Questions Bow waves are produced by waves of water
moving faster than the source producing them.
destructively interfering.
moving slower than the source producing them.
moving at the same speed as the source producing them.

138. Assessment Questions Bow waves are produced by waves of water
moving faster than the source producing them.
destructively interfering.
moving slower than the source producing them.
moving at the same speed as the source producing them.
Answer: C

139. Assessment Questions Shock waves are produced by waves of sound
constructively interfering.
destructively interfering.
moving faster than the source producing them.
that never overlap.

140. Assessment Questions Shock waves are produced by waves of sound
constructively interfering.
destructively interfering.
moving faster than the source producing them.
that never overlap.
Answer: A