1.1 reading Guide B

1. 1.1 reading Guide B 1. Definition—a disturbance that transfers energy from one place to another; Characteristics—energy travels entire distance, while matter does not; Examples—sound waves, water waves, light waves; Nonexamples—ball rolling, rock falling 2. Drawings should show how a wave was created from up-and-down or back-and-forth forces. 3. Definition—any substance that a wave moves through; Characteristics—all materials; Examples—water, the ground, a rope; Nonexamples—a wave itself

2. 4. Notes: it is energy that is transferred in a wave, not the matter that the wave moves through. In some cases, kinetic energy is transferred. The medium of the wave only moves slightly, while the wave can travel great distances; Sketch to Explain: a drawing of a water wave that shows how the medium only moves slightly while the wave travels a greater distance

3. 5. Transverse—picture: should resemble picture on SE page 13. Notes: wave in which the direction of travel is perpendicular to the direction of the disturbance; there is an up and down motion of medium; some examples include a rope and a water wave. Longitudinal—picture: should resemble picture on SE page 14. Notes: wave that travels in the same direction as the disturbance; it has many bunched-up areas known as compressions; examples are sound waves and waves on a spring.

4. 1.2 reading Guide B 1. amplitude, wavelength, and frequency 2. Crests are the highest points, or peaks of waves. Troughs are the lowest points, or valleys of waves.

5. 1.2 reading Guide B • 3. Notes: The amplitude is the distance between a line through the middle of a wave and a crest or trough. The wavelength is the distance from one wave crest to the next. The frequency is the number of wavelengths passing a fixed point in a certain amount of time. Sketch to Explain: a sketch showing amplitude, wavelength, and frequency • 4. The wave with a higher amplitude has more energy.

6. 1.2 reading Guide B 5. When frequency increases, there are more wavelengths per second, and the wavelength shortens. On the other hand, when frequency decreases, there are fewer wavelengths per second, and the wavelengths are longer. 6. Amplitude is measured by determining the compression of the medium. The frequency is measured by determining the number of wavelengths passing a fixed point in a certain amount of time. For transverse waves, the amplitude is measured by determining the distance between the wave’s position at rest and the wave’s crest or trough. The frequencies for both types of waves are measured in the same way.

7. 1.2 reading Guide B • 7. Speed = wavelength p frequency or S = λf • 8. S = 2 m/s

8. 2.1 reading Guide B 1. a mechanical wave; a vibration that travels through a gas, liquid, or solid; a longitudinal wave; transfers energy through a medium 2. Sound waves are produced by vibrations that are usually too small to see. The vibrations push and pull on the medium around them and send waves out in all directions. The vocal cords are a sound-making instrument in the human body. 3. Your vocal cords are tensed up when you are about to speak or sing. They are relaxed when you are breathing, to allow air to pass in and out of your windpipe.

9. 2.1 reading Guide B 4. The outer ear collects the waves and sends them to the ear canal where they are received by the eardrum. The eardrum begins to vibrate. The middle ear carries vibrations to the inner ear. The inner ear sends a signal to the brain. 5. The vibrating drum skin pushes against nearby air particles and compresses them. The drum skin pushes the opposite way and opens a space between it and the air particles. The back-and-forth disturbance travels to the listener. 6. a. compressions; b. areas between compressions; c. air particles

10. 2.1 reading Guide B 7. empty space; has no or very few particles; sound cannot travel through it 8. Sound waves require particles to move in order to travel. In a vacuum, there are no particles, so there is nothing for a sound wave to move. 9. the material that makes up the medium and the temperature of the medium

11. 2.1 reading Guide B 10. Particles are closest together in solid materials, so sound waves can pass faster from particle to particle. 11. The colder the temperature, the slower sound travels because the air particles don’t move as fast when it’s cold.

12. 2.2 reading Guide B 1. the quality of the highness or lowness of a sound; determined by frequency; a high-frequency wave makes a high sound; a low-frequency wave makes a low sound; a rapidly vibrating object makes a high sound; a slowly vibrating object makes a low sound 2. Students should circle the tuba. 3. Sketch should show a series of waves with 15 crests between 2 lines marking off 1 second.

13. 2.2 reading Guide B 4. 20 to 20,000 hertz 5. Infrasound waves are those waves that are below 20 hertz. They have a long wavelength and can travel great distances without losing much energy. 6. sound waves above 20,000 hertz; humans cannot hear it; many animals can hear it

14. 2.2 reading Guide B 7. A piano tuner uses tuning forks to tune pianos. Tuning forks vibrate at a natural frequency that is the same as some of the notes on the piano. The piano tuner strikes the tuning fork and then adjusts the piano so that it matches the resulting frequency. 8. A. causes sound waves to strengthen; B. results from adding the amplitude of a sound wave to the amplitude of an object’s natural vibration

15. 2.2 reading Guide B 9. 1. Most sounds are combination of waves. 2. The combination of pitches is the main factor affecting sound quality. 1. The sound of cymbals blasts out suddenly. 2. The sound of the human voice starts much more gently. 10. No. The ambulance plays the same sound the whole time, but the pitch falls as the ambulance drives away. 11. Accept any reasonable answer that includes a sound source and a moving object.

16. 2.3 reading Guide B 1. Sample answers: food sources, objects underwater, and the inside of the body 2. top tier: a sketch of echolocation in use; middle tier: use of the word echolocation in a sentence; bottom tier: sending out ultrasound waves and interpreting the returning sound echoes

17. 2.3 reading Guide B 3. instruments that use echolocation to locate objects; stands for sound navigation and ranging; can detect sounds from submarine propellers; can locate underwater objects; can find schools of fish; can be used to map the ocean floor; can be used to find sunken ships 4. Ultrasound waves cannot be heard by humans, so they can be used on humans at very high intensities without damaging hearing. 5. The ultrasound scanner can examine internal organs. One of the most well-known uses of ultrasound is to check the health of a fetus during pregnancy. Ultrasound can also break up kidney stones.

18. 2.3 reading Guide B 6. All of the pitches of the instrument, along with the resonance of the instrument itself, produce the characteristic sound of the instrument. 7. Loosen or tighten the drum skin to change the pitch. 8. The strings have loosened, and the pitch has changed.

19. 2.3 reading Guide B 9. The two inventions were the telephone and the phonograph. 10. As you speak into the mouthpiece, your sound waves cause a thin disk inside to vibrate. A microphone turns these vibrations into electrical signals. These signals are sent over wire to a switching station. Computers connect the wire to the other telephone. 11. Edison’s phonograph had a needle connected to a diaphragm that could pick up sound waves. The vibrations of the sound waves were sent to the needle, which cut into a piece of foil. To play back the sound, Edison used another needle to track along the grooves made in the foil.

20. 2.4 reading Guide B 1. Sample answers: food sources, objects underwater, and the inside of the body 2. top tier: a sketch of echolocation in use; middle tier: use of the word echolocation in a sentence; bottom tier: sending out ultrasound waves and interpreting the returning sound echoes

21. 2.4 reading Guide B 3. instruments that use echolocation to locate objects; stands for sound navigation and ranging; can detect sounds from submarine propellers; can locate underwater objects; can find schools of fish; can be used to map the ocean floor; can be used to find sunken ships 4. Ultrasound waves cannot be heard by humans, so they can be used on humans at very high intensities without damaging hearing. 5. The ultrasound scanner can examine internal organs. One of the most well-known uses of ultrasound is to check the health of a fetus during pregnancy. Ultrasound can also break up kidney stones.

22. 2.4 reading Guide B 6. All of the pitches of the instrument, along with the resonance of the instrument itself, produce the characteristic sound of the instrument. 7. Loosen or tighten the drum skin to change the pitch. 8. The strings have loosened, and the pitch has changed.

23. 2.4 reading Guide B 9. The two inventions were the telephone and the phonograph. 10. As you speak into the mouthpiece, your sound waves cause a thin disk inside to vibrate. A microphone turns these vibrations into electrical signals. These signals are sent over wire to a switching station. Computers connect the wire to the other telephone. 11. Edison’s phonograph had a needle connected to a diaphragm that could pick up sound waves. The vibrations of the sound waves were sent to the needle, which cut into a piece of foil. To play back the sound, Edison used another needle to track along the grooves made in the foil.

24. 3.1 reading Guide B 1. a disturbance that transfers energy through a field; called EM waves; most are invisible; light is made of them; they enable radios, TVs, and cell phones to send or receive information 2. A field is an area around an object through which the object can apply a force on another object without touching it. 3. EM waves form from quickly moving, electrically charged atomic particles.

25. 3.1 reading Guide B 4. electric and magnetic 5. the Sun 6. transfer of energy in the form of EM waves; different from transfer of energy through mechanical waves; can travel without any medium; does not lose energy as it moves

26. 3.1 reading Guide B 7. EM waves can travel through space because they do not need a medium. They can cross great distances because they do not lose energy in traveling. EM waves spread outward in all directions from their source. Over distance, the waves become more spread out, so less energy is found in a given area. Only a very small part of the Sun’s energy is transferred to Earth. 8. 300,000 kilometers (186,000 miles) per second 9. The vast distances of space are measured in terms of how many years or minutes it would take light to travel through them. The unit is light-years or light-minutes.

27. 3.1 reading Guide B 10. A. Students should draw reflection; B. Students should draw refraction. 11. Mechanical waves transfer both potential and kinetic energy. EM waves in a vacuum transfer potential energy, but when EM waves encounter matter, their energy can be converted into many different forms. 12. In a microwave oven, EM waves do not transfer energy to air, but when they come into contact with water particles in food, the EM waves transfer energy, causing the food to get hot.

28. 3.2 reading Guide B 1. Higher frequency waves have more energy. Lower frequency waves have less energy. 2. On the left are waves with the longest wavelengths and the lowest frequencies; on the right are the waves with the shortest wavelengths and the highest frequencies. 3. Since all EM waves move at the same speed in a vacuum, wavelength determines frequency. EM wavelengths run from about 30 kilometers to trillionths of a centimeter. EM wave frequency is measured in hertz. 4. EM waves with the longest wavelengths, and the lowest frequencies and energies; travel easily through the atmosphere and other materials; first EM waves used for telecommunication; broadcast television also uses radio waves.

29. 3.2 reading Guide B 5. Radar works by transmitting microwaves, receiving reflections of the waves from objects the waves strike, and converting these reflections into visual images on a screen. It is used to control air traffic, analyze the weather, and measure the speed of a moving vehicle. 6. the part of the EM spectrum that human eyes can see; from about 1014 Hz to about 1015 Hz

30. 3.2 reading Guide B 7. consists of EM frequencies between microwaves and visible light; type of EM radiation most often associated with heat; it cannot be seen, but can be felt; examples of objects that give off infrared rays include the Sun, a fire, a radiator, a toaster, and hot coals

31. 3.2 reading Guide B 8. The higher frequency of EM waves results in higher energy for ultraviolet light. This higher energy can damage our tissues. Infrared waves have lower energy and do not damage cells. 9. X-rays Only—can cause cancer over time; have frequencies from about 1016 to about 1021 Hz; are useful for diagnosing bone fractures and dense tumors; pass easily through soft tissues but are filtered out by denser matter; Both—have high frequencies and energy; can be used for medical imaging; Gamma Rays Only—have the highest frequencies and energies of all EM waves; have frequencies from about 1019 to about 1024 Hz; can be used to kill cancer cells and fight tumors; can penetrate soft and hard tissues of the body