1. - What Are Waves?
Waves and Energy
A wave is a disturbance that transfers energy from place to place.
Waves travel through water (or medium, but they do not carry the water (or the duck) (the object or medium) with them.
The material through which a wave travels is through a medium. Gases (air), solids, and liquids all act as mediums.

2. How do Waves Transfer Energy?
Mechanical waves, not electromagnetic waves, travel through a medium. Sound waves are mechanical waves.
Waves travel through a medium, but they don’t carry the medium with them. For instance, when the wave passes, the duck and the water return to where they started. Think of yourself on a raft. If you had not way to propel the raft (oars); you’d remain in the same spot.
Electromagnetic waves do not require a medium

3. Electromagnetic Waves
Using what you know, complete the Venn Diagram comparing Mechanical Waves and Electromagnetic Waves
Mechanical Waves
Electromagnetic Waves

4. What causes waves?
Vibration – a repeated back-and-forth or up-and-down motion.
Mechanical waves are produced when a source of energy causes a medium to vibrate.
Energy is always required to make a wave.

5. Types of Waves
Transverse (across) moves at a right angle to the source of the energy.
The highest point is called the crest
The lowest point is called the trough
Exactly in between the high and the low point is known as its resting point.
Amplitude is the maximum distance that the particles of the medium carrying the wave move away from their rest positions. It is the amount of energy a sound wave carries.
Wavelength – the distance between two correspoinding parts of a wave.
Frequency – The number of complete waves that pass a given point in a certain amount of time. Measured in Hertz

6. - What Are Waves?
Transverse Waves
Waves that move through the medium at right angles to the direction in which the waves travel are called transverse waves.

7. - What Are Waves?
Longitudinal Waves
Longitudinal waves move the medium parallel to the direction in which the waves travel. Sound is carried through longitudinal waves.

8. All Waves have amplitude, wavelength and frequency
Amplitude is the maximum distance that the particles of the medium carrying the wave move away from their rest positions. It is the amount of energy a sound wave carries.
Wavelength – the distance between two correspoinding parts of a wave.
Frequency – The umber of complete waves that pass a given point in a certain amount of time. Measured in Hertz (Hz).
An example of Hertz is :
If two waves pass you every second, then the frequency of the wave is 2 per second, or 2Hz.

9. Amplitude, Wavelength, and Frequency
- Properties of Waves
Amplitude, Wavelength, and Frequency
The basic properties of all waves are amplitude, wavelength, and frequency.
amplitude

10. What is happening to this wave?
The energy is increasing because the frequency is increasing. As frequency increases, pitch gets higher. Below is an example of frequency increasing.

11. Waves Quiz
Which set of waves is longitudinal? Type M for top, A for bottom.
Which set of waves is transverse? Type M for top, A for bottom.
Where is the crest on the top wave?
Where is compression occurring?
Where is rarefaction occurring?
Where is the trough?
Where is the amplitude?
Where is the wave’s resting point?
Which wave represents wave lengths?

12. Wave Quiz
Use your responders to answer the questions at the front of the room. Do not press select until you have typed in all 9 answers.
- Properties of Waves P D T U E L I

13. Calculating Frequency
- Properties of Waves
Calculating Frequency
The speed of a wave on a rope is 50 cm/s and its wavelength is 10 cm. What is the wave’s frequency?
Plan and Solve
What quantity are you trying to calculate?
The frequency of a wave = __ Hz
What formula contains the given quantities and the unknown quantity?
Frequency = Speed/Wavelength
Perform the calculation.
Frequency = Speed/Wavelength = 50 cm/s/10 cm
Frequency = 5/s = 5 Hz

14. Calculating Frequency
- Properties of Waves
Calculating Frequency
The speed of a wave on a rope is 50 cm/s and its wavelength is 10 cm. What is the wave’s frequency?
Look Back and Check
Does your answer make sense?
The wave speed is 50 cm per second. Because the distance from crest to crest is 10 cm, five crests will pass a point every second.

15. Interactions of Waves Reflection, Refraction, Diffraction
Reflection – When a wave hits a surface through which it can’t pass. This is called a reflection.
The law of reflection states that the angle of incidence equals the angle of reflection.
Refraction – The bending of waves due to a change in speed.
When a wave enters a new medium at an angle, one side of the wave changes speed before the other side, causing the wave to bend.
Bending occurs because the two sides of the wave travel at different speeds.
Diffraction – When a wave moves around a barrier or through an opening in a barrier and it spreads out.

16. When waves hit a surface, they move 3 ways, through reflection, refraction and diffraction
The Law of Reflection: The angle of incidence equals the angle of reflection. All types of waves are reflected. You can see your face in a mirror because light waves from your face are reflected back from the mirror’s shiny surface.
Refraction
When a wave enters a new medium at an angle, one side of the wave changes speed before the other side, causing the wave to bend. The bending of waves due to a change in speed is refraction.

17. The Third Way: Diffraction
- Interactions of Waves
When a wave moves around a barrier or through an opening in a barrier, it bends and spreads out.

18. Interference – the interaction between waves that meet.
More about diffraction:
- Interactions of Waves
Interference – the interaction between waves that meet.
The interference that occurs when waves combine to make a wave with a larger amplitude is called constructive interference.
The interference that occurs when waves combine to make a wave with a smaller amplitude is called destructive interference.

19. Standing Wave
If you tie a rope to a doorknob and continuously shake the free end, waves will come back (reflect). It can make the wave look like it’s standing still.
See next slide

20. - Interactions of Waves
Standing Waves
If the incoming wave and a reflected wave have just the right frequency, they produce a combined wave that appears to be standing still.

21. Answer the Questions Below
- Interactions of Waves
Answer the Questions Below
Answer the questions below:
Question
Answer
How are waves reflected?
What is refraction?
When does diffraction occur?
What is a standing wave?

22. - Seismic Waves
Types of Seismic Waves
Seismic waves include P waves, S waves, and surface waves.

23. - Seismic Waves
Motion of a Tsunami
This graph shows the rate at which a tsunami moves across the Pacific Ocean. Use the data plotted on the graph to answer the following questions.

24. Motion of a Tsunami Reading Graphs:
- Seismic Waves
Motion of a Tsunami
Reading Graphs:
What two variables are plotted on the graph?

25. - Seismic Waves
Types of Seismic Waves
Earthquakes that occur underwater, like the one off the coast of Chile in 1960, can produce huge surface waves on the ocean called tsunamis.

26. All have frequency, amplitude and wavelength
Waves
All have frequency, amplitude and wavelength
can be
can be
Transverse
Longitudinal
contain
contain
contain
contain
Crests
Troughs
Compressions
Rarefactions

27. Table of Contents The Nature of Sound Properties of Sound Music
How You Hear Sound
Using Sound
Sound Video:
Play Discovery Sound Video Here

28. - The Nature of Sound
Sound Waves
Sound is a disturbance (vibration) that travels through a medium as a longitudinal (move the medium parallel to the source) wave. As a gong vibrates, it creates sound waves that travel through the air.

29. How Sound Travels
Sounds travel through the states of matter (medium), known as gases (air), solids, and liquids.

30. Interactions of Sound Waves
- The Nature of Sound
Interactions of Sound Waves
Sound waves reflect off objects, diffract through narrow openings and around barriers, and interfere with each other.
Echo!

31. - The Nature of Sound
The Speed of Sound
The speed of sound depends on the elasticity, density, and temperature of the medium the sound travels through.
Which type of medium does sound travel the fastest according to the chart?
The closer together molecules are, the faster sound is able to travel. You can devise this from the chart.

32. Temperature and the Speed of Sound
- The Nature of Sound
Temperature and the Speed of Sound
The speed of sound in dry air changes as the temperature changes. The graph shows data for the speed of sound in air at temperatures from – 10ºC to 20ºC.

33. Temperature and the Speed of Sound
- The Nature of Sound
Temperature and the Speed of Sound
Reading Graphs:
What is the speed of sound in air at –10ºC?
The speed at –10ºC is 325 m/s.

34. Temperature and the Speed of Sound
- The Nature of Sound
Temperature and the Speed of Sound
Interpreting Data:
Does the speed of sound increase or decrease as temperature increases?
The speed of sound increases as air temperature increases.

35. Temperature and the Speed of Sound
- The Nature of Sound
Temperature and the Speed of Sound
Reading Graphs:
What is the speed of sound in air at –10ºC?
The speed at –10ºC is 325 m/s.

36. Temperature and the Speed of Sound
- The Nature of Sound
Temperature and the Speed of Sound
Predicting:
What might be the speed of sound at 30ºC?
At 30ºC, the speed of sound might be 349 m/s.

37. Sound
A disturbance that travels through a medium as a longitudinal wave.
Carry energy through a medium without moving the particles of the medium along. Each particle of the medium vibrates as the disturbance passes. When the disturbance reaches your ears, it causes your eardrums to vibrate, and you hear sound which is interpreted by your brain.

38. Graphic Organizer Sound Longitudinal waves Intensity Frequency
travels as
has properties
Longitudinal waves
Intensity
Frequency
speed depends on
is heard as
is heard as
Elasticity
Density
Temperature
Loudness
Pitch

39. Interactions of Sound waves
Sound waves can reflect when they hit a surface, and this may cause an echo
Sound can diffract through openings
Sound can interfere with each other constructively (add to the sound waves) or destructively (cancel each other out)

40. The Speed of Sound
At room temperature, sound travels at about 343 m/s, which is much faster than most jets!
Sound travels at different speeds through different mediums and at different temperatures.
Speed of sound depends on temperature, elasticity and the density of the medium.

41. - The Nature of Sound
Elasticity
Elasticity is the ability of a material to bounce back after being disturbed. You can model elasticity by representing the particles in a medium as being held together by springs. The more elasticity, the faster sound travels.

42. - The Nature of Sound
Density
Density is how much mass there is in a give volume. The volumes of the cubes are the same, but the brass has more mass. The greater the density, the less sound gets through.

43. - Properties of Sound
Loudness
The loudness of different sounds is compared using a unit called the decibel (dB). Depends on two factors: the amount of energy it takes to make the sound and the distance from the source of the sound.
Intensity is the amount of energy a sound wave carries per second through a unit area.

44. Pitch The higher the pitch, the greater the Frequency of the wave.
- Properties of Sound
Pitch
The pitch of a sound that you hear depends on the frequency of the sound wave.
The higher the pitch, the greater the Frequency of the wave.

45. Changing Pitch
- Properties of Sound
When you sing, you change pitch using your vocal cords. Your vocal cords are located in your voice box, or larynx.

46. Examples of what pitch looks like
Medium Pitch
High Pitch (high frequency)
Lowest Pitch (low wave frequency)
Lower Pitch but not nearly as low as the wave to the left.

47. - Properties of Sound
The Doppler Effect
The change in frequency of a wave as its source moves in relation to an observer is called the Doppler effect. When a sound source moves, the frequency of the waves changes because the motion of the source adds to the motion of the waves.

48. - Properties of Sound
The Doppler Effect
When the plane travels almost as fast as the speed of sound, the sound waves pile up in front of the plane. This pile up is the “sound barrier.”

49. - Music
Sound Quality
The sound quality of musical instruments results from blending a fundamental tone with its overtones. Resonance also plays a role in sound quality.

50. Groups of Musical Instruments
There are three basic groups of musical instruments: stringed instruments, wind instruments, and percussion instruments.

51. Acoustics and Reverberation
Acoustics – the study of how sounds interact with each other and the environment.
Acoustics matter in our classroom because the more sounds reverberate in the classroom, the less you’ll be able to hear what I say.
Can you think of other places acoustics matter?

52. - How You Hear Sound
The Human Ear
The outer ear funnels sound waves, the middle ear transmits the waves inward, and the inner ear transforms sound waves into a form that travels to your brain.

53. Hearing Loss Can be caused by: Heredity Injury Infection
Exposure to loud sounds
Aging

54. - Using Sound
Echolocation
Some animals, including bats and dolphins, use echolocation to navigate and to find food.

55. - Using Sound
Sonar
A sonar device sends out ultrasound waves and then detects the reflected waves.

56. Light and Color Light and Color Reflection and Mirrors
Refraction and Lenses
Seeing Light
Using Light
Video:

57. When Light Strikes an Object
- Light and Color
When Light Strikes an Object
When light strikes an object, the light can be reflected, transmitted, or absorbed.
Explain difference between the three.

58. Transparent
Transmits most of the light that strikes it. The light passes right through without being scattered. Clear glass, water and air are examples.
Translucent
Scatters light as it passes through. Frosted glass, and wax paper are examples.
Opaque
Reflects or absorbs all of the light that strikes it. Light cannot pass through them. Wood, metal, and tightly woven fabrics are opaque.

59. Light Absorption and Reflection Give objects their colors.

60. - Light and Color
The Color of Objects
The color of an opaque object is the color of the light it reflects.

61. - Light and Color
The Color of Objects
The color of a transparent or translucent object is the color of the light it transmits.

62. - Light and Color
Combining Colors
As pigments are added together, fewer colors of light are reflected and more are absorbed.

63. Reflection of Light Rays
- Reflection and Mirrors
Reflection of Light Rays
The two ways in which a surface can reflect light are regular reflection and diffuse reflection.

64. - Reflection and Mirrors
Concave Mirrors
A mirror with a surface that curves inward like the inside of a bowl is a concave mirror.

65. - Reflection and Mirrors
Concave Mirrors
Ray diagrams show where an image forms and the size of the image. The steps below show how to draw a ray diagram.

66. - Reflection and Mirrors
Concave Mirrors
Concave mirrors can form either virtual images or real images.

67. - Reflection and Mirrors
Convex Mirrors
A mirror with a surface that curves outward is called a convex mirror.

68. Complete the diagram below
- Reflection and Mirrors
Complete the diagram below
Concave Mirror
Convex Mirror

69. - Refraction and Lenses
Refraction of Light
When light rays enter a medium at an angle, the change in speed causes the rays to bend or change direction.

70. Refraction
When sunlight passes through a prism, rays are bent, or refracted
Prism: separates the colors of light (dispersion)
rainbows are caused by refraction in the atmosphere

71. - Refraction and Lenses
Bending Light
The index of refraction of a medium is a measure of how much light bends as it travels from air into the medium. The table shows the index of refraction of some common mediums.

72. Bending Light Interpreting Data:
- Refraction and Lenses
Bending Light
Interpreting Data:
Which medium causes the greatest change in the direction of a light ray?
Diamond causes the greatest change in the direction of a light ray traveling from air.

73. Bending Light Interpreting Data:
- Refraction and Lenses
Bending Light
Interpreting Data:
According to the table, which tends to bend light more: solids or liquids?
According to the graph, most solids bend light more than liquids do (quartz is an exception).

74. Bending Light Predicting:
- Refraction and Lenses
Bending Light
Predicting:
Would you expect light to bend if it entered corn oil at an angle after traveling through glycerol? Explain.
You would not expect light to bend if it entered corn oil at an angle after traveling through glycerol, because corn oil and glycerol have the same value for the index of refraction.

75. When light passes through water
Waves are refracted and bends so it looks like objects you put in the water bends because light slows down.
videos/search?q=stev e+spangler+refractio n&FORM=VIRE1#vie w=detail&mid=1C66 ADFAEEB1970FCF11 1C66ADFAEEB1970 FCF11
WATER

76. - Refraction and Lenses
A lens is a curved piece of glass or other transparent material.

77. - Refraction and Lenses
An object’s position relative to the focal point determines whether a convex lens forms a real image or a virtual image.

78. - Refraction and Lenses
A concave lens can produce only virtual images because parallel light rays passing through the lens never meet.

79. - Seeing Light
Vision
Know the parts of the eye and their functions.
Pages 631 and 632 of you text – draw the eyeball, the functions of what you have labeled, and draw a schematic of what happens when light hits your eye (p 630)
Retina is like a screen on a camera.
The part of the eye that absorbs visible light waves with the highest frequencies is: blue cones.

80. - Seeing Light
What happens when light enters the eye and passes through the lens? The light undergoes REFRACTION and forms an image on the retina.

81. How do we see? How You See Objects Light enters the eye.
- Seeing Light
How do we see?
How You See Objects
Light enters the eye.
Light focuses on the retina.
An image forms.
Rods and cones send signals to the brain.

82. - Using Light
Optical Instruments
A telescope forms enlarged images of distant objects. Telescopes use lenses or mirrors to collect and focus light from distant objects.

83. Optical Instruments
- Using Light
A microscope uses a combination of lenses to produce and magnify an image.

84. - Using Light
Optical Instruments
The lens of the camera focuses light to form a real, upside-down image on film in the back of the camera.

85. - Using Light
Lasers
Laser light consists of light waves that all have the same wavelength, or color. The waves are coherent, or in step.

86. - Using Light
Optical Fibers
The floodlight in the swimming pool gives off light rays that travel to the surface. If the angle of incidence is great enough, a light ray is completely reflected back into the water. This complete reflection of light by the inside surface of a medium is called total internal reflection.

87. - Using Light
Optical Fibers
Optical fibers can carry a laser beam for long distances because the beam stays totally inside the fiber as it travels.

88. Graphic Organizer Type of Mirror Effect on Light Rays Type of Image
Plane
Regular reflection
Virtual
Concave
Converge
Real or virtual
Convex
Spread out
Virtual
Type of lens
Effect on Light Rays
Type of Image
Convex
Converge
Real or virtual
Concave
Spread out
Virtual

89. Table of Contents The Nature of Electromagnetic Waves
Waves of the Electromagnetic Spectrum
Producing Visible Light
Wireless Communication

90. Electromagnetic Waves
The Nature of Electromagnetic Waves
Electromagnetic Waves
Believe it or not, you are being “showered” all the time, not by rain but by waves.

91. What Is an Electromagnetic Wave?
The Nature of Electromagnetic Waves
What Is an Electromagnetic Wave?
An electromagnetic wave consists of vibrating electric and magnetic fields that move through space at the speed of light.

92. Models of Electromagnetic Waves
The Nature of Electromagnetic Waves
Models of Electromagnetic Waves
Many properties of electromagnetic waves can be explained by a wave model. Only some light waves pass through a polarizing filter. The light that passes through vibrates in only one direction and is called polarized light.

93. What Is the Electromagnetic Spectrum?
Waves of the Electromagnetic Spectrum
What Is the Electromagnetic Spectrum?
The electromagnetic spectrum is the complete range of electromagnetic waves placed in order of increasing frequency.
The part of the eye that absorbs visible light waves with the highest frequencies are: blue cones.

94. Waves of the Electromagnetic Spectrum
Scientific Notation
Frequencies of waves often are written in scientific notation. A number in scientific notation consists of a number between 1 and 10 that is multiplied by a power of 10. To write 150,000 Hz in scientific notation, move the decimal point left to make a number between 1 and 10:
In this case, the number is 1.5. The power of 10 is the number of spaces you moved the decimal point. In this case, it moved 5 places:
150,000 Hz = 1.5 X 105 Hz

95. Scientific Notation Practice Problem
Waves of the Electromagnetic Spectrum
Scientific Notation
Practice Problem
A radio wave has a frequency of 5,000,000 Hz. Write this number in scientific notation.
5.0 X 106 Hz

96. Electromagnetic waves
Graphic Organizer
Electromagnetic waves
travel at the speed of
consist of
have different
Magnetic fields
Electric fields
Wavelengths
Frequencies
Light

97. Electromagnetic Waves
Waves of the Electromagnetic Spectrum
Electromagnetic waves are all around you–in your home, your neighborhood, and your town.

98. The Electromagnetic Spectrum
Waves of the Electromagnetic Spectrum
The Electromagnetic Spectrum
Q. Which electromagnetic waves have the shortest wavelength?
A. Gamma rays have the shortest wavelength.
Q. Which electromagnetic waves have the lowest frequency?
A. Radio waves have the lowest frequency.

99. Producing
Visible Light
Incandescent Lights
An incandescent light is a light bulb that glows when a filament inside it gets white hot.

100. Producing
Visible Light
Neon Lights
A neon light is a sealed glass tube that contains neon gas.

101. Comparing and Contrasting
Producing
Visible Light
Comparing and Contrasting
Ordinary Light Bulb
Tungsten-Halogen
Feature
Fluorescent
Vapor
Neon
Bulb Material
Holes in data from book.
Glass
Quartz
Glass
Glass
Glass
Hot/Cool
Hot
Very Hot
Cool
Cool
Cool
Tungsten filament and nitrogen gas and argon gas inside
Has tungsten filament and a halogen gas inside
Has neon or argon gas and solid sodium or mercury inside
Makeup
A gas and a powder coating inside
Has neon gas inside
More efficient than ordinary bulb
Efficiency
Not efficient
Very efficient
Very efficient
Very efficient

102. Wireless
Communication
Radio and Television
In AM transmissions, the amplitude of a radio wave is changed. In FM transmissions, the frequency is changed.

103. Comparing Frequencies
Wireless
Communication
Comparing Frequencies
The table shows the ranges of radio broadcast frequencies used for AM radio, UHF television, FM radio, and VHF television.

104. Comparing Frequencies
Wireless
Communication
Comparing Frequencies
Interpreting Data:
In the table, what units of measurement are used for frequency?
Kilohertz (kHz) and megahertz (MHz)

105. Comparing Frequencies
Wireless
Communication
Comparing Frequencies
Interpreting Data:
Which type of broadcast shown in the table uses the highest frequency radio waves? Which uses the lowest frequency waves?
UHF television uses the highest frequency radio waves, and AM radio broadcast uses the lowest frequency radio waves.

106. Comparing Frequencies
Wireless
Communication
Comparing Frequencies
Calculating:
Which type of broadcast uses waves with the shortest wavelength?
UHF television uses waves with the highest frequency and therefore the shortest wavelength.

107. Comparing Frequencies
Wireless
Communication
Comparing Frequencies
Inferring:
A broadcast uses a frequency of 100 MHz. Can you tell from this data if it is a television or radio program? Explain.
You cannot tell from this data if it is a television or radio program, because VHF television and FM radio both broadcast radio waves with a frequency of 100 MHz.

108. Wireless
Communication
Cellular Phone System
In the cellular phone system, cellular phones transmit and receive radio waves that travel to the nearest tower.

109. Communication Satellites
Wireless
Communication
Communication Satellites
In the Global Positioning System (GPS), signals from four satellites are used to pinpoint a location on Earth.

110. Using Prior Knowledge Wireless Communication What You Know
Cellular phones don’t use wires.
Radio and television signals travel through the air.
What You Learned
The signals for radio and television programs are carried by radio waves.
The signals can be transmitted by changing either the amplitude or the frequency of the radio waves.
Cellular phones transmit and receive signals using microwaves.

111. Electromagnetic waves
Graphic Organizer
Electromagnetic waves
travel at the speed of
consist of
have different
Magnetic fields
Electric fields
Wavelengths
Frequencies
Light