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1 TO GO TO ANY OF THE PAGES LISTED BELOW, CLICK ON ITS TITLE CHAPTER 17 Waves What is a wave? How do waves travel through matter? 3 Kinds of Waves Enrichment Activity for Lesson What are the features of a wave? 5 Properties of Waves Enrichment Activity for Lesson How are waves reflected? 7 Reflection Enrichment Activity for Lesson How are waves refracted? 9 THE BIG IDEA Integrating Earth Science: Tsunami: How big can a wave get? 10 Chapter 17 Key Term Review 11 Chapter 17 Test 12 Chapter 17 Answer Key 14 (c) by Pearson Education, Inc./Globe Fearon/Pearson Learning Group. All rights reserved. Waves: CHAPTER 17, page 1

2 17-1 What is a wave? Explain the relationship between each of the terms in the following pairs. 1. waves, energy 2. mechanical waves, matter 3. medium, particles 4. light waves, empty space 5. air, medium 6. radio waves, electromagnetic waves Skills: analyzing, interpreting diagrams Use the diagram to answer the following questions. 1. What is the medium for the waves in this diagram? 2. What are the waves transferring? 3. How do water molecules move as the wave moves forward? 4. What happens to the piece of wood as the wave passes by? Why? (c) by Pearson Education, Inc./Globe Fearon/Pearson Learning Group. All rights reserved. Waves: CHAPTER 17, page 2

3 17-2 How do waves travel through matter? Complete the following. 1. The low point of a transverse wave is called a. 2. The crest is the of a transverse wave. 3. In a wave, the particles of the medium move back and forth along the direction of the wave motion. 4. The part of a longitudinal wave where the particles of the medium are far apart is called a. 5. Compression is the part of a longitudinal wave where the particles of the medium are. 6. The particles of the medium move at right angles to the direction in which the wave travels in a wave. Skills: labeling, interpreting diagrams, classifying Complete the following. 1. What type of wave is shown in Diagram A? 2. Label a crest and a trough on the wave in Diagram A. 3. What type of wave is shown in Diagram B? 4. Label a compression and a rarefaction on the wave in Diagram B. (c) by Pearson Education, Inc./Globe Fearon/Pearson Learning Group. All rights reserved. Waves: CHAPTER 17, page 3

4 Kinds of Waves Enrichment Activity for Lesson 17-2 Skills: identifying, classifying Decide whether each picture below shows energy transfer by a transverse wave or by a longitudinal wave. Write your answers in the spaces provided (c) by Pearson Education, Inc./Globe Fearon/Pearson Learning Group. All rights reserved. Waves: CHAPTER 17, page 4

5 17-3 What are the features of a wave? Use the equation speed = frequency wavelength to complete the table below. SPEED, FREQUENCY, AND WAVELENGTH Speed (m/s) Frequency (Hz) Wavelength (m) , Skills: calculating, interpreting a diagram Use the diagram below to answer the following questions. 1. What is the wavelength of wave A? 2. What is the frequency of wave A? 3. What is the speed of wave A? 4. What is the wavelength of wave B? 5. What is the frequency of wave B? 6. What is the speed of wave B? (c) by Pearson Education, Inc./Globe Fearon/Pearson Learning Group. All rights reserved. Waves: CHAPTER 17, page 5

6 Properties of Waves Enrichment Activity for Lesson 17-3 Skills: interpreting graphs, calculating PART A The graphs below show the properties of two different waves. Study the graphs. Then, answer the questions. 1. Which wave has the greater amplitude? How much greater? 2. Which wave has the greater wavelength? How much greater? 3. Which wave has the greater frequency? State the frequency of this wave in hertz (Hz) and in waves per second. 4. State the frequency of the other wave. 5. Which wave do you think has the greater speed? Why? PART B Complete the table. Speed (m/s) Frequency (Hz) Wavelength (m) (c) by Pearson Education, Inc./Globe Fearon/Pearson Learning Group. All rights reserved. Waves: CHAPTER 17, page 6

7 17-4 How are waves reflected? Complete the following. 1. What is an incident wave? 2. What is the law of reflection? 3. What is the normal? 4. What is a right angle? 5. What is a reflected wave? 6. What is reflection? Skills: measuring, diagramming The arrows in the diagrams below represent incident waves. Use a protractor to construct the normal and the reflected wave in each diagram. Follow the law of reflection. (c) by Pearson Education, Inc./Globe Fearon/Pearson Learning Group. All rights reserved. Waves: CHAPTER 17, page 7

8 Reflection Enrichment Activity for Lesson 17-4 Skills: interpreting diagrams, applying concepts The diagrams below show various properties of reflection. Use the diagrams to answer the questions. 1. What is represented by the letter i on Diagram A? 2. What is represented by the letter r on Diagram A? 3. What must be true about i and r? 4. What does the dotted line on Diagrams A and B represent? What is its relationship to the barrier? 5. Use a protractor to measure angle i on Diagram B. 6. Use a protractor to correctly draw the reflected wave on Diagram B. Label the reflected wave and angle r. 7. What is different about the barrier in Diagram C? 8. What do you notice about the incident waves and the reflected waves in Diagram C? 9. How do you account for this? 10. How would the reflected waves look if the surface was flat? (c) by Pearson Education, Inc./Globe Fearon/Pearson Learning Group. All rights reserved. Waves: CHAPTER 17, page 8

9 17-5 How are waves refracted? Write true if the statement is true. If the statement is false, change the underlined term to make the statement true. Write your answers in the spaces provided. 1. The bending of a wave is called reflection. 2. A light wave speeds up as it moves from a more dense to a less dense medium. 3. When a wave moves at an angle from a less dense medium to a more dense medium, it is bent away from the normal. 4. In order for a wave to be bent toward the normal, it must move at an angle from a more dense medium to a less dense medium. 5. Refraction is caused by a change in wave speed. 6. The laws of refraction describe how waves are bent when they move from one medium to another. 7. When a wave travels from air into water, it will bend away from the normal. Skills: interpreting tables, relating information Use the table to answer the following questions. DENSITIES OF SEVERAL MATERIALS Material Density (g/cm 3 ) Helium Air Water 1.00 Seawater 1.02 Bone 1.8 Gasoline 0.07 Hydrogen If a light wave moved from air into helium, what would happen to its speed? 2. If a light wave moved from gasoline into hydrogen, in which direction would it bend? 3. If a light wave moved from water into seawater, in what direction would it bend? Would the wave speed up or slow down? 4. Why would a light wave speed up if it moved from air into hydrogen? (c) by Pearson Education, Inc./Globe Fearon/Pearson Learning Group. All rights reserved. Waves: CHAPTER 17, page 9

10 THE Big IDEA Chapter 17 Tsunami: How big can a wave get? Refer to the article, call outs, and Figure on pages 370 and 371 of your text to answer the following questions. Integrating Earth Science 1. How big can a tsunami get? 2. What causes tsunamis? 3. How far can a tsunami travel? 4. Why are tsunamis more dangerous for docked boats than for boats in the open ocean? 5. What kind of instrument is used to detect if a tsunami is heading for Hawaii? Skill: inferring 1. Why do you think that tsunamis occur most commonly in the Pacific Ocean? 2. Why do you think it is safer to be up on high ground when a tsunami is coming? Science Log Writing Activity Complete the Science Log on a separate sheet of paper. To complete the Big Idea Online, go to Follow the online instructions. (c) by Pearson Education, Inc./Globe Fearon/Pearson Learning Group. All rights reserved. Waves: CHAPTER 17, page 10

11 Chapter 17 Key Term Review In the spaces provided, write the term that best fits each description. Unscramble the letters in brackets [ ] to spell a topic that is discussed in this chapter. Write the topic in the space provided at the bottom of the page. Then, explain the meaning of the topic in one or two sentences. 1. Disturbances that transfer energy through a medium [ ] 2. Wave in which the particles of the medium move back and forth in the direction of the wave motion [ ] 3. Part of a medium in which the particles of a longitudinal wave are close together [ ] 4. Number of complete waves per unit of time [ ] 5. Height of a wave [ ] 6. Wave that bounces back from a barrier [ ] 7. Bending of a wave moving at an angle from one medium to another [ ] 8. Wave that transfers energy through empty space [ ] 9. Substance through which mechanical waves can travel [ ] 10. Wave that strikes a barrier [ ] 11. Line perpendicular to a barrier [ ] Topic: Explanation: (c) by Pearson Education, Inc./Globe Fearon/Pearson Learning Group. All rights reserved. Waves: CHAPTER 17, page 11

12 Chapter 17 Test Interpreting Diagrams Use the diagrams to answer the following questions. B 1. What kind of wave is shown in Diagram A? 2. What kind of wave is shown in Diagram B? 3. What does Diagram C represent? 4. What are the high points of a transverse wave? 5. What are the low points of a transverse wave? 6. What are the parts of a longitudinal wave in which the particles are close together? 7. What are the parts of a longitudinal wave in which the particles are spread out? 8. What happens when a wave strikes a barrier in its path? Multiple Choice Write the letter of the term or phrase that best completes the statement or answers the question. 1. W h i c h o f t h e f o l l o w i n g t e r m s i s n o t r e l a t e d t o t h e o t h e r s? a. crest b. compression c. trough d. transverse wave 2. T h e b e n d i n g o f w a v e s w h e n t h e y p a s s f r o m o n e m e d i u m t o a n o t h e r i s c a l l e d a. reflection. b. interference. c. normal. d. refraction. 3. T h e d i s t a n c e b e t w e e n t w o n e i g h b o r i n g c r e s t s o r t r o u g h s i s c a l l e d a. wavelength. b. amplitude. c. hertz. d. frequency. 4. I f t h e a n g l e o f i n c i d e n c e i s 6 0, t h e a n g l e o f r e f l e c t i o n i s a. 60. b. 90. c. 0. d (c) by Pearson Education, Inc./Globe Fearon/Pearson Learning Group. All rights reserved. Waves: CHAPTER 17, page 12

13 Chapter 17 Test (continued) 5. A w a v e t h a t c a n t r a v e l t h r o u g h e m p t y s p a c e i s a. mechanical. b. transverse. c. longitudinal. d. electromagnetic. 6. A w a v e t h a t s t r i k e s a b a r r i e r i s c a l l e d a. a reflected wave. b. a normal wave. c. a n i n c i d e n t w a v e. d. a r e f r a c t e d w a v e. 7. O f t h e f o l l o w i n g w a v e s, t h e k i n d t h a t d o e s n o t r e q u i r e a m e d i u m i s a. light. b. sound. c. water. d. sound and water. 8. T h e h i g h p o i n t o f a t r a n s v e r s e w a v e i s c a l l e d t h e a. trough. b. compression. c. crest. d. rarefaction. 9. W h e n a w a v e m o v e s a t a n a n g l e f r o m a l e s s d e n s e m e d i u m i n t o a m o r e d e n s e m e d i u m, i t i s b e n t a. at a 90 angle. b. toward the normal. c. away from the normal. d. at a 45 angle W h e n a l i g h t w a v e m o v e s f r o m a m o r e d e n s e m e d i u m i n t o a l e s s d e n s e m e d i u m, i t s s p e e d a. increases. b. decreases. c. remains the same. d. becomes zero. 11. Waves transfer a. energy. b. matter. c. particles. d. light A n o t h e r n a m e f o r t h e h e i g h t o f a w a v e i s a. frequency. b. hertz. c. wavelength. d. amplitude A n y m a t e r i a l t h a t a m e c h a n i c a l w a v e c a n t r a v e l t h r o u g h i s c a l l e d a. a barrier. b. a medium. c. the normal. d. reflection T h e s p e e d o f a w a v e t h a t h a s a f r e q u e n c y o f 2 5 H z a n d a w a v e l e n g t h o f 3 9 m i s a. 25 m/s. b m/s. c. 975 m/s. d m/s T h e p a r t o f a l o n g i t u d i n a l w a v e i n w h i c h t h e p a r t i c l e s o f t h e m e d i u m a r e c l o s e t o g e t h e r i s c a l l e d a a. crest. b. trough. c. compression. d. rarefaction. Written Response Answer the following questions in complete sentences. 16. ANALYZE: A ripple wave from a boat passes beneath a lily pad floating on the surface of a lake. What happens to the lily pad? Explain. 17. COMPARE AND CONTRAST: How are sound waves similar to light waves? How are they different? (c) by Pearson Education, Inc./Globe Fearon/Pearson Learning Group. All rights reserved. Waves: CHAPTER 17, page 13

14 Answer Key CHAPTER 17: WAVES 17-1 What is a wave? 1. Waves transfer energy from one place to another. 2. Mechanical waves can only transfer energy through some form of matter. 3. When a mechanical wave moves through a medium, the particles of the medium do not travel with the wave. 4. Light waves can travel through empty space. 5. Air can serve as a medium for sound waves. 6. Radio waves are an example of electromagnetic waves. 1. water 2. energy 3. in small circles 4. The wood moves up and down with the water. It does not move forward with the wave. This is because the particles of a medium do not travel with a wave. Only the energy of the wave moves from one place to another How do waves travel through matter? 1. trough 2. high point 3. longitudinal 4. rarefaction 5. close together 6. transverse 1. transverse wave 2. 1: crest; 2: trough 3. longitudinal wave 4. 1: compression; 2: rarefaction 17-2 How do waves travel through matter? Enrichment Activity: Kinds of Waves 1. transverse 2. longitudinal 3. transverse 4. transverse 5. longitudinal 6. transverse (string vibrating) or longitudinal (sound wave produced) 7. longitudinal 8. transverse 17-3 What are the features of a wave? , m 2. 1 Hz 3. 1 m/s m 5. 2 Hz 6. 1 m/s 17-3 What are the features of a wave? Enrichment Activity: Properties of Waves PART A 1. wave B; twice as great as wave A 2. wave A; twice as great as wave B 3. wave B; 2 Hz, or 2 waves per second 4. 1 Hz, or 1 wave per second 5. Both have the same speed because the frequency of wave B is twice the frequency of wave A, but the wavelength of wave A is twice the wavelength of wave B. PART B How are waves reflected? 1. wave that strikes a barrier 2. law that states that the angle of incidence is equal to the angle of reflection 3. a line at a right angle to a barrier 4. an angle equal to wave that bounces off a barrier 6. bouncing of a wave after striking a barrier 17-4 How are waves reflected? Enrichment Activity: Reflection 1. angle of incidence 2. angle of reflection 3. They must be equal. 4. the normal; It is at a right angle (90º) to the barrier º 6. Check students diagrams. The measure of angle r should be 55º. 7. The surface is very bumpy, instead of flat. 8. The incident waves are all parallel to one another, but the reflected waves are all going in different directions. 9. For each point on the barrier, the normal is different. As a result, the reflected waves go in different directions depending on the slant of the surface at that point. 10. They would all be parallel to one another. (c) by Pearson Education, Inc./Globe Fearon/Pearson Learning Group. All rights reserved. Waves: CHAPTER 17, page 14

15 Answer Key 17-5 How are waves refracted? 1. refraction 2. true 3. toward 4. away from 5. true 6. true 7. toward 1. Its speed would increase. 2. away from the normal 3. toward the normal; slow down 4. Waves speed up when they travel from a more dense medium into a less dense medium. The Big Idea meters higher than the average size of ocean waves 2. earthquakes or volcanic eruptions on the seafloor 3. thousands of kilometers 4. Tsunamis are safe for boats on the open ocean because their waves are only about 1 m high in deep water. However, when tsunamis get close to shore, their waves can be 18 m higher than normal, making it very dangerous for docked boats. 5. seismographs 1. Tsunamis occur most commonly in the Pacific Ocean because the Ring of Fire is located there; Earthquakes, which cause tsunamis, occur frequently in this region. 2. When a tsunami hits land, it is safer to be on high ground above the height of the tsunami because the tsunami is not likely to hit that area. Lower areas are more likely to be hit by the tsunami. CHAPTER 17: WAVES Chapter Test Interpreting Diagrams 1. transverse 2. longitudinal 3. reflection of a wave from a barrier 4. crests 5. troughs 6. compressions 7. rarefactions 8. The wave bounces back, or is reflected, from the barrier. Multiple Choice 1. b 2. d 3. a 4. a 5. d 6. c 7. a 8. c 9. b 10. a 11. a 12. d 13. b 14. c 15. c Written Response 16. The lily pad moves up and down in place as the wave passes by, but it does not move across the lake with the wave. This is because a wave is the movement of energy, not of matter. The water particles move in place as the wave passes by, and the lily pad shares the motion of the water particles. 17. One similarity is that sound and light waves both transfer energy. One difference is that sound waves are mechanical waves that require a medium to travel through, while light waves are electromagnetic waves that can travel through empty space. CHAPTER 17: WAVES Key Term Review 1. waves 2. longitudinal wave 3. compression 4. frequency 5. amplitude 6. reflected wave 7. refraction 8. electromagnetic wave 9. medium 10. incident wave 11. normal Topic: rarefaction Explanation: Rarefaction is the part of a medium in which the particles of a longitudinal wave are far apart. (c) by Pearson Education, Inc./Globe Fearon/Pearson Learning Group. All rights reserved. Waves: CHAPTER 17, page 15