Waves. Chapter Resources. Includes: Glencoe Science. Reproducible Student Pages. Teacher Support and Planning TRANSPARENCY ACTIVITY MASTERS ASSESSMENT

Transcription

1 Glencoe Science Chapter Resources Waves Includes: Reproducible Student Pages ASSESSMENT Chapter Tests Chapter Review HANDS-ON ACTIVITIES Lab Worksheets for each Student Edition Activity Laboratory Activities Foldables Reading and Study Skills activity sheet MEETING INDIVIDUAL NEEDS Directed Reading for Content Mastery Directed Reading for Content Mastery in Spanish Reinforcement Enrichment Note-taking Worksheets TRANSPARENCY ACTIVITY MASTERS Section Focus Activity Teaching Transparency Activity Assessment Transparency Activity Teacher Support and Planning Content Outline for Teaching Spanish Resources Teacher Guide and Answers

2 Directed Reading for Content Mastery Overview Waves Directions: Complete the concept map using the terms in the list below. reflection medium incidence energy mechanical space Waves 1. are called 3. waves that need a are repeating disturbances that transfer 4. obey the law of 2. which states that the angle of 5. through matter or 6. equals the angle of reflection Directions: For each of the following write the letter of the phrase that best completes the sentence. 7. The high point of a transverse wave is. a. a rarefaction b. the frequency c. the crest 8. The less dense region of a compression wave is called. a. a rarefaction b. the frequency c. the crest 9. The number of wavelenghts that pass a fixed point each second is of a wave. a. a rarefaction b. the frequency c. the crest Waves 19

3 Directed Reading for Content Mastery Section 1 The Nature of Waves Section 2 Wave Properties Directions: Determine if each statement is true or false. If it is false, change the italicized word(s) to correct the sentence. 1. Waves transfer matter as they travel. 2. A wave will travel only as long as it has energy to carry. 3. Anything that moves up and down or back and forth in a rhythmic way is vibrating. 4. All waves need a medium in order to travel. 5. Transverse and congressional waves are the two types of mechanical waves. 6. In a compressional wave the matter in the medium moves back and forth at right angles to the direction that the wave travels. 7. In a transverse wave the matter in the medium moves back and forth in the same direction that the wave travels. 8. In a transverse wave, the peak of the wave is the crest and the lowest spot is the trough. 9. The refraction of a wave is how many wavelengths pass a fixed point each second. 10. The speed of a wave is determined by multiplying the wavelength by the frequency. 11. In a compressional wave, the denser the medium is at the compressions the smaller its amplitude. 12. In a transverse wave, the higher the amplitude, the more energy it carries. 20 Waves

4 Directed Reading for Content Mastery Section 3 The Behavior of Waves Directions: The illustration below represents the law of reflection. Copy the letters from the illustration next to the terms they stand for. 1. normal Directions: Answer the questions in the space provided. 6. If you are picking up a coin on the bottom of the pool, can you just reach for where the coin appears to be? Why or why not? 7. What causes waves to bend? a b c d e 2. angle of reflection 3. reflected beam 4. incident beam 5. angle of incidence 8. What are the two types of interference and how do they work? a. b. 9. What is a standing wave? Waves 21

5 Directed Reading for Content Mastery Key Terms Waves Directions: Match the term in Column I with the correct definition in Column II by writing the correct letter in the space to the left. Column I Column II 1. amplitude a. a repeating disturbance that transfers energy through matter or space 2. compressional b. highest point of a wave 3. crest 4. diffraction 5. frequency 6. interference 7. medium 8. rarefaction 9. refraction 10. resonance 11. standing wave 12. transverse 13. trough 14. wave 15. wavelength c. bending of a wave as it moves from one medium to another d. a material that a wave transfers energy through e. lowest point of a wave f. bending of a wave as it passes around a barrier g. matter moves at right angles to the direction the wave travels h. spread apart portion of a compressional wave i. when two or more waves overlap and combine to form a new wave j. matter moves in same direction as wave travels k. distance between one point on a wave and the nearest point just like it l. when waves continuously interfere with each other m. how many wavelengths pass a fixed point each second n. ability of an object to vibrate by absorbing energy at its natural frequency o. measure of the energy in a wave 22 Waves

6 1 Reinforcement The Nature of Waves Directions: Answer the following questions on the lines provided. 1. What is a wave? 2. What travels on a wave? 3. How is a wave created? 4. What is a mechanical wave? 5. List the two types of mechanical waves and define them. a. b. 6. What type of wave is a sound wave? 7. How does sound travel through a medium? 8. Describe the motion of something floating in water waves. 9. What causes ocean waves? 10. What are seismic waves? Waves 27

7 2 Reinforcement Wave Properties Directions: Study Figure 1, then identify each part by filling in the blanks below. Figure Directions: Answer the following questions on the lines provided. 5. List three characteristics of a wave that you can measure. 6. What is meant by the frequency of a wave? What is the unit? If the frequency of a given wave increases, what happens to the wavelength? Directions: Fill out the following table by describing how to measure each of the quantities for the two types of waves. Wave Wavelength Amplitude 8. transverse 9. compressional 10. What is the velocity of a wave with a frequency of 6 Hz and a wavelength of 2 m? 28 Waves

8 3 Reinforcement The Behavior of Waves Directions: Answer the following questions on the lines provided. 1. How is an echo produced? 2. When light is reflected, how are the angle of incidence and the angle of reflection related? 3. Compare and contrast refraction and diffraction. 4. What happens to the direction of a light wave when it passes from a less dense medium such as air into a more dense medium such as glass? 5. Why does a tree in the path of sunlight create a shadow instead of the light spreading around the tree? 6. What happens when two waves approach and pass each other? 7. When is a standing wave produced? Waves 29

9 1 Enrichment Sonic Booms You have learned that a sound wave is a compression wave. A sound wave s speed is affected by the medium through which the wave travels. Temperature also affects the speed of sound. Higher temperatures increase the velocity of sound waves. At room temperature (about 20 C) the speed of sound is about 343 meters per second. The Sound Barrier So what would happen if something, like an airplane, traveled faster than the speed of sound? For years physicists and engineers argued about whether it was even possible to fly faster than sound. Think about this for a moment. If the plane is making a certain sound from the roaring of the jet engines, what would happen when the jet flew faster than the sound it was making? This point, at which something is moving as fast as the speed of the sound it is making, is called the sound barrier. Some people thought that if a plane flew faster than the speed of sound it would explode or break apart from the force it generated. In 1947 a man named Chuck Yeager proved this was not true. He was the first man to fly faster than the speed of sound. 1. What is the sound barrier? 2. Describe what happens when a jet flies faster than the speed of sound. 3. How does a sonic boom happen? 4. What is a Mach cone? Today all kinds of supersonic jets fly faster than the speed of sound. When a jet breaks the sound barrier, a loud noise or sonic boom is heard. If the plane is close enough to the ground, the boom can break glass and damage property. It is a forceful blast of sound. The reason it is so forceful is because of the compression waves. As the plane flies faster and faster, the air molecules begin to compress on each other. They compress at an increasing rate.eventually the energy of compressed molecules becomes too great and they explode in all directions. This explosion makes the sound known as the sonic boom. In the Mach Cone The explosion continues to occur as the plane moves along, but you can only hear it as it passes over you. You are in what scientists call the Mach cone. The faster the plane goes, the narrower the Mach cone becomes. If the plane is flying high enough you will not be in the Mach cone and will not hear any boom. Supersonic planes are told to fly high enough to avoid causing any damage from their sonic booms. That s why we hear fewer sonic booms these days. 30 Waves

10 2 Enrichment Superposition Principle Two water waves are traveling in opposite directions. What happens when they meet? The amplitudes of the waves add together. At the instant the waves overlap, the amplitudes of each point in the overlap region is the sum of the amplitudes of the two waves. In other words, a wave with a 2-m amplitude crosses another wave with a 3-m amplitude, making a wave with a 5-m amplitude at that one instant. Each wave travels through the water making its own contribution to the new wave s amplitude. This is true no matter what any other wave is doing. This characteristic of waves is called the superposition principle. The diagram below shows the superposition of two waves at point P. P P P Before During After 1. If two waves with amplitudes of +4 cm and +2 cm pass through point P, what is the maximum possible displacement of point P? Draw three scale diagrams showing the waves before they meet, when they meet, and after they meet. 2. The amplitudes of two waves are +5 cm and 3 cm. What is the new wave formed after the two waves meet? Make a drawing showing the waves before, during, and after their interaction. 3. Two water waves, one with an amplitude of +3 m and another with an amplitude of 3 m approach and meet each other in a lake. Describe what happens to the waves as they meet each other. Waves 31

11 3 Enrichment You may have heard that some opera singers can break a glass with their voice. Maybe you saw a joke on television about someone shattering glass with sound? Can this really happen? Under certain circumstances, sound waves can have a shattering effect on glass. It all starts with the glass. Some types are more easily shattered than others, but in theory any glass can be broken. When you tap a glass, say a water glass, you can hear a slight sound or ringing. That sound is the resonant frequency of the glass. Each glass has its own resonant frequency. When tapped, the glass vibrates back and forth. The thickness and purity of the glass will determine the rate at which it vibrates. Fine crystal usually has resonant frequencies that are easy to hear. Singing Vibrations When a singer, or some other sound source, produces the exact frequency (pitch) of the glass, it will vibrate. This is resonance, or one vibration making another vibration. Glass, Sound Waves, and Opera Singers If the amplitude of the singer s vibration frequency increases, the glass vibrations will also increase. The problem for the glass is that it is made of a material that has molecules bound together in tight positions. Air is like a liquid and can move freely; the molecules in glass cannot. If the amplitude and resulting force of the initial vibration source gets too big it will vibrate the glass much too hard. The molecules in the glass cannot move as fast or as far as they are being pushed. The result is that the glass will shatter. Yelling Won t Help But yelling loudly at a glass most likely will not break it. The resonant frequencies of glass are usually very high. It also takes a pure tone, like the kind opera singers can produce, to resonate the glass. This is difficult to do. However, if you play an electric musical instrument with a pure and high note at a loud volume, it s possible that an expensive piece of crystal may shatter. 1. What are some things that determine the resonant frequency of glass? 2. What is resonance? 3. How can a singer make a glass resonate? 4. Why does the glass break from sound? 32 Waves

12 Section 1 Note-taking Worksheet Waves The Nature of Waves A. Wave a repeating disturbance or movement that transfers through matter or space 1. Molecules pass energy on to molecules. 2. Waves carry energy without transporting. 3. All waves are produced by something that. 4. Medium a through which a wave travels. a. May be solid, liquid, or b. Not all waves need a medium to travel through; example: B. Mechanical waves waves that can travel only through 1. Transverse waves matter in the medium moves back and forth the direction that the wave travels; example: 2. Compressional waves matter in the medium moves that the wave travels; example: 3. Combinations not purely transverse or compressional; examples: water waves, waves Section 2 Wave Properties A. Ways waves differ 1. How much they carry 2. How they travel 3. How they look a. waves have crests the highest points, and troughs the lowest points. b. Compressional waves have dense regions called and less dense regions called. B. Wavelength the distance between one point in the wave and Waves 33

13 Note-taking Worksheet (continued) C. Frequency how many pass a fixed point each second 1. Expressed in 2. As frequency increases, wavelength. 3. The frequency of a wave equals the rate of of the source that creates it. D. Wave, or v,describes how fast the wave moves forward. 1. = wavelength, or v = λ f. 2. Light waves travel than sound waves. 3. Sound waves travel faster in and than in gas. 4. Light waves travel faster in and than in liquids and solids. E. Amplitude a measure of the in a wave 1. The more energy a wave carries, the its amplitude. 2. Amplitude of waves is related to how tightly the medium is pushed together at the compression. a. The the compressions, the larger the amplitude is and the more energy the wave carries. b. The less dense the rarefactions, the the amplitude and the more energy the wave carries. 3. Amplitude of waves Section 3 a. The distance from the crest or trough of a wave to the of the medium b. Example: how high an ocean wave appears above the water level The Behavior of Waves A. Reflection occurs when a wave strikes an object and of it. 1. types of waves can be reflected. 2. The angle of incidence of a wave is always equal to the angle of. a. Normal an imaginary line to a reflective surface b. Angle of the angle formed by the wave striking the surface and the normal c. Angle of the angle formed by the reflected wave and the normal 34 Waves

14 Note-taking Worksheet (continued) B. Refraction the of a wave caused by a change in its speed as it moves from one medium to another 1. The greater the change in speed is, the the wave bends. 2. When a wave passes into a material that slows it down, the wave is bent the normal. 3. When a wave passes into a material that speeds it up, the wave is bent the normal. C. Diffraction an object causes a wave to change direction and around it 1. If the obstacle is than the wavelength, the wave diffracts a lot. 2. If the obstacle is much than the wavelength, the wave does not diffract much. 3. The larger the obstacle is compared to the wavelength, the the waves will diffract. D. Interference the ability of two or more waves to and form a new wave 1. Waves pass right through each other and continue in. 2. New wave exists only while the two original waves continue to. 3. Constructive interference waves together 4. Destructive interference waves from each other E. Standing waves a wave pattern that stays in 1. Form when waves of equal and amplitude that are traveling in directions continuously interfere with each other 2. Nodes the places where two waves cancel each other F. Resonance the ability of an object to by absorbing energy at its natural frequency Waves 35

15 Chapter Review Waves Part A. Vocabulary Review Directions: Choose the correct term from the list below and write it in the space beside each definition. amplitude compression diffraction compressional wave crest frequency interference law of reflection medium rarefaction reflection refraction resonance standing wave transverse wave trough wavelength waves 1. when a wave strikes an object and bounces off 2. repeating disturbances that transfer energy through matter or space 3. highest point of a transverse wave 4. region where the medium is crowded and dense in a compressional wave 5. wave that makes matter in the medium move back and forth at right angles to the direction the wave travels 6. ability of two or more waves to combine and form a new wave 7. lowest point of a transverse wave 8. material through which a wave transfers energy 9. the bending of waves around a barrier 10. less dense region of a compressional wave 11. ability of an object to vibrate by absorbing energy at its natural frequency 12. wave in which matter in the medium moves back and forth in the same direction the wave travels 13. distance between one point in a wave and the nearest point just like it 14. measure of how many wavelengths pass a fixed point each second 15. the angle of incidence is equal to the angle of reflection 16. measure of the energy in a wave 17. a special type of wave pattern that forms when waves of equal wavelength and amplitude traveling in opposite directions continuously interfere with each other Assessment 18. the bending of a wave caused by a change in its speed as it moves from one medium to another Waves 37

16 Chapter Review (continued) Part B. Concept Review Directions: Use the diagram below to answer questions 1 5. A a B c b d 1. What type of wave is wave A? 2. Which wave carries more energy? 3. What do points a and c represent? 4. What do points b and d represent? 5. How does the frequency of wave B compare with that of wave A? Directions: Using the equation v = λ f, find the missing values. 6. What is the velocity of a wave with a frequency of 760 Hz and a wavelength of 0.45 m? Assessment 7. A wave with a wavelength of 15 m travels at 330 m/s. Calculate its frequency. Directions: Answer the following questions on the lines provided. 8. How do scientists know that seismic waves can be either compressional or transverse? 9. Why do surfers like water waves with high amplitudes? 10. Will loud sounds from traffic near a school break glass objects inside the school? Explain. 38 Waves

17 1 Section Focus Transparency Activity Wave to the Camera How many waves can you pick out in this scene? Is light described as a wave? If you were there when this photograph was taken, you might also mention the sound waves. Transparency Activities 1. Describe the different waves in this picture. 2. If you are swimming underwater, can you still hear the noises around you? What does this tell you about sound waves? 3. What does light travel through as it goes from the Sun to the eyes of an underwater swimmer? 44 Waves

18 2 Section Focus Transparency Activity Big Fiddle, Little Fiddle Have you ever heard the instruments below played? If you have, you probably noticed that the bass produces a much lower sound than the violin. The difference in the sounds is related to differences in the waves each instrument produces. 1. Name some muscial instruments. How are the instruments you named played? 2. A cello is bigger than a violin but smaller than a bass. How do you think the sound made by a cello compares to the sounds made by violins and basses? Waves 45 Transparency Activities

19 3 Section Focus Transparency Activity Wave Art This artistic picture shows how waves can make fascinating patterns in water. When waves travelling toward the wall reach the openings, they pass through them. After passing through the openings, the waves create new patterns as they overlap on the other side of the wall. Transparency Activities 1. What do the waves look like before they reach the wall? What do they look like after passing through the opening? 2. Where do the waves in the photograph overlap? 3. What do you think this picture would look like if both holes were plugged? 46 Waves

20 2 Teaching Transparency Amplitude of Waves Activity Crest Amplitude Amplitude Trough Transparency Activities Rest position Waves 47

21 Teaching Transparency Activity (continued) 1. What is the highest point of a wave called? 2. What is the lowest point of a wave called? 3. How is the amplitude of a wave measured? 4. How is wavelength measured? 5. What is frequency? 6. What does the amplitude of a wave measure? Transparency Activities 48 Waves

22 Assessment Transparency Activity Waves Directions: Carefully review the table and answer the following questions. Electromagnetic Waves in Your Life Type of wave Radio waves Microwaves Red light Green light Blue light X rays Shortest wavelength (cm) Longest wavelength (cm) 10,000, Electromagnetic waves of different wavelengths have been given different names. According to the table, which type of electromagnetic wave can have a wavelength greater than 5 m? A Radio waves C Red light B Microwaves D Blue light 2. According to the table, which type of electromagnetic wave can have a wavelength of cm? F Radio waves H Red light G Microwaves J Blue light 3. If a device were emitting an electromagnetic wave of cm, what kind of device would it be? A Radio C Flashlight B Microwave oven D X-ray machine Transparency Activities Waves 49