1. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu How to Use This Presentation To View the presentation as a slideshow with effects select “View” on the menu bar and click on “Slide Show.” To advance through the presentation, click the right-arrow key or the space bar. From the resources slide, click on any resource to see a presentation for that resource. From the Chapter menu screen click on any lesson to go directly to that lesson’s presentation. You may exit the slide show at any time by pressing the Esc key.

2. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter Presentation Transparencies Image and Math Focus Bank Bellringers Standardized Test Prep CNN Videos Visual Concepts Resources

3. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu The Energy of Waves Table of Contents Section 1 The Nature of Waves Section 2 Properties of Waves Section 3 Wave Interactions Chapter 20

4. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 The Nature of Waves Bellringer What do you think of when you hear the word wave? Write a brief description of what you think a wave is. Then, write a short paragraph describing a time you might have experienced waves. Write your responses in your science journal. Chapter 20

5. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 The Nature of Waves Objectives Describe how waves transfer energy without transferring matter. Distinguish between waves that require a medium and waves that do not. Explain the difference between transverse and longitudinal waves. Chapter 20

6. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 The Nature of Waves Wave Energy A wave is any disturbance that transmits energy through matter or empty space. Energy can be carried away from its source by a wave. However, the material through which the wave travels does not move with the energy. Chapter 20

7. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 The Nature of Waves Chapter 20

8. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 The Nature of Waves Wave Energy, continued Waves and Work As a wave travels, it does work on everything in its path. The waves in a pond do work on the water to make it move up and down. The waves also do work on anything floating on the water’s surface. The fact that the water and floating objects move tells you that the waves are transferring energy. Chapter 20

9. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 The Nature of Waves Wave Energy, continued Energy Transfer Through a Medium Most waves transfer energy by the vibration of particles in a medium. A medium is a substance through which a wave can travel. Sound waves, water waves, and seismic waves all need a medium through which to travel. Chapter 20

10. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 The Nature of Waves Wave Energy, continued Energy Transfer Without a Medium Visible light waves, microwaves, radio waves, and X rays are examples of waves can transfer energy without going through a medium. These waves are electromagnetic waves. Although electromagnetic waves do not need a medium, they can go through matter. Chapter 20

11. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 The Nature of Waves Types of Waves Transverse Waves are waves in which the particles vibrate perpendicularly to the direction the wave is traveling. Transverse waves are made up of crests and troughs. Water waves, waves on a rope, and electromagnetic waves are examples of transverse waves. Chapter 20

12. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 The Nature of Waves Types of Waves, continued Longitudinal Waves are waves in which the particles vibrate back and forth along the path that the waves moves. Longitudinal waves are made up of compressions and rarefactions. Waves on a spring are longitudinal waves. Chapter 20

13. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 The Nature of Waves Chapter 20

14. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 The Nature of Waves Types of Waves, continued Sound Waves are longitudinal waves. Sound waves travel by compressions and rarefactions of air particles, as shown below. Chapter 20

15. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 The Nature of Waves Types of Waves, continued Combinations of Waves A transverse waves and a longitudinal wave can combine to form a surface wave. Surface waves look like transverse waves, but the particles of the medium move in circles rather than up and down. Chapter 20

16. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Properties of Waves Bellringer Draw a longitudinal wave and a transverse wave in your science journal. Label the parts of each wave. Chapter 20

17. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Properties of Waves Objectives Identify and describe four wave properties. Explain how frequency and wavelength are related to the speed of a wave. Chapter 20

18. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Properties of Waves Amplitude The amplitude of a wave is the maximum distance that the particles of a medium vibrate from their rest position. Chapter 20 A wave with a large amplitude carries more energy than a wave with a small amplitude does.

19. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Properties of Waves Wavelength A wavelength is the distance between any point on a wave to an identical point on the next wave. A wave with a shorter wavelength carries more energy than a wave with a longer wavelength does. Chapter 20

20. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Properties of Waves Frequency Frequency is the number of waves produced in a given amount of time. Frequency is usually expressed in hertz (Hz). One hertz equals one wave per second. If the amplitudes are equal, high-frequency waves carry more energy than low-frequency waves. Chapter 20

21. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Properties of Waves Chapter 20

22. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Properties of Waves Wave Speed Wave Speed is the speed at which a wave travels. Wave speed (v) can be calculated using wavelength ( ) and frequency (f), by using the wave equation, which is shown below: v   f Chapter 20

23. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Properties of Waves Chapter 20

24. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Properties of Waves Wave Speed, continued Frequency and Wavelength Relationship Frequency and wavelength are inversely related. So, if one value is doubled, the other value will be cut in half. The wave speed of a wave in a certain medium is the same no matter what the wavelength is. So, the wavelength and frequency depend on the wave speed, not the other way around. Chapter 20

25. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Properties of Waves Characteristics of a Wave Chapter 20 Click below to watch the Visual Concept. You may stop the video at any time by pressing the Esc key. Visual Concept

26. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Wave Interactions Bellringer Write the symbols v, f, and in your science journal. Then, write what each symbol stands for, and how each symbol relates to the other two. Chapter 20

27. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Wave Interactions Objectives Describe reflection, refraction, diffraction, and interference. Compare destructive interference with constructive interference. Describe resonance, and give examples. Chapter 20

28. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Wave Interactions Reflection Reflection happens when a wave bounces back after hitting a barrier. Light waves reflecting off an object allow you to see that object. A reflected sound wave is called an echo. Waves are not always reflected when they hit a barrier. A wave is transmitted through a substance when it passes through the substance. Chapter 20

29. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Wave Interactions Refraction Refraction is the bending of a wave as the wave pass from one medium to another at an angle. When a wave moves from one medium to another, the wave’s speed and wavelength changes. As a result, the wave bends and travels in a new direction. Chapter 20

30. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Wave Interactions Refraction, continued Refraction of Different Colors When light waves from the sun pass through a water droplet or a prism, the light is refracted. But the different colors in sunlight are refracted by different amounts, so the light is spread out into its separate colors. Chapter 20

31. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Wave Interactions Diffraction Diffraction is the bending of waves around a barrier or through an opening. The amount of diffraction of a wave depends on its wavelength and the size of the barrier or opening the wave encounters. Chapter 20

32. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Wave Interactions Interference Interference is the result of two or more waves overlapping. Constructive Interference happens with the crests of one wave overlap with the crests of another wave or waves. The troughs of the waves also overlap. The result is a new wave that has a larger amplitude than the original waves had. Chapter 20

33. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Wave Interactions Interference, continued Destructive Interference happens with the crests of one wave and the troughs of another wave overlap. The new wave have a smaller amplitude than the original waves had. When the waves involved in destructive interference have the same amplitude and meet each other at just the right time, the result is no wave at all. Chapter 20

34. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Wave Interactions Chapter 20

35. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Wave Interactions Interference, continued Standing Waves are waves that appear to be standing still. A standing wave only looks as if it is standing still. Waves are actually going in both directions. In a standing wave, certain parts of the wave are always at the rest position because of total destructive interference. Other parts have a large amplitude because of constructive interference. Chapter 20

36. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Wave Interactions Interference, continued The frequencies at which standing waves form are called resonant frequencies. Resonance happens when an object vibrating at or near the resonant frequency of a second object causes the second object to vibrate. An example of resonance is shown on the next slide. Chapter 20

37. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Wave Interactions Interference, continued Chapter 20

38. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu The Energy of Waves Use the terms below to complete the concept map on the next slide. Chapter 20 Concept Map transverse frequency waves longitudinal wave speed amplitude energy medium

39. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu The Energy of Waves Chapter 20

40. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu The Energy of Waves Chapter 20

41. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu End of Chapter 20 Show

42. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Reading Read each of the passages. Then, answer the questions that follow each passage. Chapter 20 Standardized Test Preparation

43. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Passage 1 On March 27, 1964, a powerful earthquake rocked Alaska. The earthquake started on land near Anchorage, and the seismic waves spread quickly in all directions. The earthquake created a series of ocean waves called tsunamis in the Gulf of Alaska. In the deep water of the gulf, the tsunamis were short and far apart. But as these waves entered the shallow water surrounding Kodiak Island, off the coast of Alaska, they became taller and closer together. Continued on the next slide Chapter 20 Standardized Test Preparation

44. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Passage 1, continued Some reached heights of nearly 30 m! The destructive forces of the earthquake and tsunamis killed 21 people and caused $10 million in damage to Kodiak, which made this marine disaster the worst in the town’s 200-year history. Chapter 20 Standardized Test Preparation

45. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 1. In the passage, what does tsunami mean? A a seismic wave B an earthquake C an ocean wave D a body of water Chapter 20 Standardized Test Preparation

46. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 1. In the passage, what does tsunami mean? A a seismic wave B an earthquake C an ocean wave D a body of water Chapter 20 Standardized Test Preparation

47. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 2. Which of these events happened first? F The tsunamis became closer together. G Tsunamis entered the shallow water. H Tsunamis formed in the Gulf of Alaska. I An earthquake began near Anchorage. Chapter 20 Standardized Test Preparation

48. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 2. Which of these events happened first? F The tsunamis became closer together. G Tsunamis entered the shallow water. H Tsunamis formed in the Gulf of Alaska. I An earthquake began near Anchorage. Chapter 20 Standardized Test Preparation

49. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 3. Which conclusion is best supported by information given in the passage? A Kodiak had never experienced a tsunami before 1964. B Tsunamis and an earthquake were the cause of Kodiak’s worst marine disaster in 200 years. C Tsunamis are common in Kodiak. D The citizens of Kodiak went into debt after the 1964 earthquake. Chapter 20 Standardized Test Preparation

50. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 3. Which conclusion is best supported by information given in the passage? A Kodiak had never experienced a tsunami before 1964. B Tsunamis and an earthquake were the cause of Kodiak’s worst marine disaster in 200 years. C Tsunamis are common in Kodiak. D The citizens of Kodiak went into debt after the 1964 earthquake. Chapter 20 Standardized Test Preparation

51. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Passage 2 Resonance was partially responsible for the destruction of the Tacoma Narrows Bridge, in Washington. The bridge opened in July 1940 and soon earned the nickname Galloping Gertie because of its wavelike motions. These motions were created by wind that blew across the bridge. The wind caused vibrations that were close to a resonant frequency of the bridge. Because the bridge was in resonance, it absorbed a large amount of energy from the wind, which caused it to vibrate with a large amplitude. Continued on the next slide Chapter 20 Standardized Test Preparation

52. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Passage 2, continued On November 7, 1940, a supporting cable slipped, and the bridge began to twist. The twisting of the bridge, combined with high winds, further increased the amplitude of the bridge’s motion. Within hours, the amplitude became so great that the bridge collapsed. Luckily, all of the people on the bridge that day were able to escape before it crashed into the river below. Chapter 20 Standardized Test Preparation

53. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 1. What caused wavelike motions in the Tacoma Narrows Bridge? A wind that caused vibrations that were close to the resonant frequency of the bridge B vibrations from cars going over the bridge C twisting of a broken support cable D an earthquake Chapter 20 Standardized Test Preparation

54. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 1. What caused wavelike motions in the Tacoma Narrows Bridge? A wind that caused vibrations that were close to the resonant frequency of the bridge B vibrations from cars going over the bridge C twisting of a broken support cable D an earthquake Chapter 20 Standardized Test Preparation

55. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 2. Why did the bridge collapse? F A supporting cable slipped. G It absorbed a great amount of energy from the wind. H The amplitude of the bridge’s vibrations became great enough. I Wind blew across it. Chapter 20 Standardized Test Preparation

56. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 2. Why did the bridge collapse? F A supporting cable slipped. G It absorbed a great amount of energy from the wind. H The amplitude of the bridge’s vibrations became great enough. I Wind blew across it. Chapter 20 Standardized Test Preparation

57. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 20 Standardized Test Preparation Interpreting Graphics Use the figure below to answer the questions that follow.

58. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 20 Standardized Test Preparation 1. This wave was generated in a laboratory investigation. What is the wavelength of the wave? A 1.5 cm B 1.7 cm C 2.0 cm D 2.7 cm

59. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 20 Standardized Test Preparation 1. This wave was generated in a laboratory investigation. What is the wavelength of the wave? A 1.5 cm B 1.7 cm C 2.0 cm D 2.7 cm

60. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 20 Standardized Test Preparation 2. If the frequency of the wave shown were doubled, what would the wavelength of the wave be? F 0.85 cm G 1.7 cm H 3.4 cm I 5.4 cm

61. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 20 Standardized Test Preparation 2. If the frequency of the wave shown were doubled, what would the wavelength of the wave be? F 0.85 cm G 1.7 cm H 3.4 cm I 5.4 cm

62. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 20 Standardized Test Preparation 3. What is the amplitude of the wave shown? A 0.85 cm B 1.7 cm C 2.7 cm D There is not enough information to determine the answer.

63. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 20 Standardized Test Preparation 3. What is the amplitude of the wave shown? A 0.85 cm B 1.7 cm C 2.7 cm D There is not enough information to determine the answer.

64. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 20 Standardized Test Preparation Math Read each question, and choose the best answer.

65. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 20 Standardized Test Preparation 1. How is the product of 5  5  5  2  2  2  2 expressed in exponential notation? A 3 5  4 2 B 5 3  2 4 C 5 7  2 7 D 10 7

66. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 20 Standardized Test Preparation 1. How is the product of 5  5  5  2  2  2  2 expressed in exponential notation? A 3 5  4 2 B 5 3  2 4 C 5 7  2 7 D 10 7

67. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 20 Standardized Test Preparation 2. Mannie purchased 8.9 kg of dog food from the veterinarian. How many grams of dog food did he purchase? F 8,900 g G 890 g H 89 g I 0.89 g

68. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 20 Standardized Test Preparation 2. Mannie purchased 8.9 kg of dog food from the veterinarian. How many grams of dog food did he purchase? F 8,900 g G 890 g H 89 g I 0.89 g

69. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 20 Standardized Test Preparation 3. What is the area of a rectangle whose sides are 3 cm long and 7.5 cm long? A 10.5 cm 2 B 12 cm 2 C 21 cm 2 D 22.5 cm 2

70. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 20 Standardized Test Preparation 3. What is the area of a rectangle whose sides are 3 cm long and 7.5 cm long? A 10.5 cm 2 B 12 cm 2 C 21 cm 2 D 22.5 cm 2

71. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 20 Standardized Test Preparation 4. An underwater sound wave traveled 1.5 km in 1 s. How far would it travel in 4 s? F 5.0 km G 5.5 km H 6.0 km I 6.5 km

72. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 20 Standardized Test Preparation 4. An underwater sound wave traveled 1.5 km in 1 s. How far would it travel in 4 s? F 5.0 km G 5.5 km H 6.0 km I 6.5 km

73. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 20 Standardized Test Preparation 5. During a tennis game, the person serving the ball is allowed only 2 serves to start a point. Hannah plays a tennis match and is able to use 50 of her 63 first serves to start a point. What is the best estimate of Hannah’s first-service percentage? A 126% B 88% C 81.5% D 79%

74. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 20 Standardized Test Preparation 5. During a tennis game, the person serving the ball is allowed only 2 serves to start a point. Hannah plays a tennis match and is able to use 50 of her 63 first serves to start a point. What is the best estimate of Hannah’s first-service percentage? A 126% B 88% C 81.5% D 79%

75. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 The Nature of Waves Chapter 20

76. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 The Nature of Waves Chapter 20

77. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Properties of Waves Chapter 20

78. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Wave Interactions Chapter 20

79. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 20 Standardized Test Preparation

80. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Properties of Waves Chapter 20