Sound 2 PDF

Sound 2  Agenda 1. Describe how moving vibrations form a wave. Page 60 - 63 2. Learn how animals use ears to detect sound. 3. Understand how a microphone converts sound into electrical signals. 4. How sound is used. Review  Review Sound is f...

Sound 2  Agenda 1. Describe how moving vibrations form a wave. Page 60 - 63 2. Learn how animals use ears to detect sound. 3. Understand how a microphone converts sound into electrical signals. 4. How sound is used. Review  Review Sound is formed by a __________ of particles that travel through the air or another medium. A. Vibration B. Force C. Speed D. Acceleration  Review Label the parts of the wave: Crest Wavelength A C Wavelength Trough Amplitude B Amplitude Crest D Trough  Review Compression of the sound wave is when particles are ____________. A. Spread apart (expand) B. Compressed (squeezed together)  Review What does the wavelength/frequency show? A. How loud a sound is B. How fast a sound is C. The pitch of the sound D. The height of the wave  Review What does the amplitude show? A. How loud a sound is B. How fast a sound is C. The pitch of the sound D. The width of the wave  Review What type of waves are sound waves? A. Radio waves B. Light waves C. Transverse waves D. Logitudinal waves Vocabulary  Vocabulary 1 Echo (echoes) 2 Using echoes to find things. 2 4 A device that converts energy from one form to Echolocation another. 3 Sonar 1 The reflection of sound waves. A device which sends out sound waves 4 Transducer 3 and measures their reflection to map an area.  Vocabulary A sound which is below the range of the human 1 Infrasonic sound 1 ear. 2 3 A material (can be solid, liquid, or gas) Ultrasonic sound which a wave travels through. A sound which is above the range of the human 3 Medium 2 ear. A system for detecting the direction, 4 Radar 4 distance, and speed of objects, using high frequency waves. How Sound Waves Travel  How Sound Waves Travel Sound waves travel through a medium by vibrating the molecules in the matter. High elasticity allows sound to travel faster. Elasticity, ability of a deformed material body to return to its original shape and size when the forces causing the deformation are removed. Highly elastic Solid Liquids Gases Elasticity and Sound  Review Sound waves cannot travel through _________ A. Vacuum B. Outer space C. Water D. A & B  Converting Sound A transducer is something which converts energy from one form to another. Sound transducers take sound energy and turn it into electrical energy (or turn electrical energy into sound waves). For example, microphones and loudspeakers are types of transducer. sound waves sound waves electrical energy  Echoes Sound waves can be reflected when they hit a medium. An echo is a reflected sound wave. Sound waves can be reflected when they hit smooth or hard mediums. Echos are used by some animals to help them understand what is around them. This is called echolocation. How We Detect Sounds  How We Detect Sound Animals, including humans, have complex ears to detect sounds. Sound waves carry vibrations to the outer ear. This makes your eardrum vibrate. Your eardrum passes the vibrations onto 3 tiny bones (ossicles) in the middle ear.  How We Detect Sound Animals, including humans, have complex ears to detect sounds. The ossicles transfer the brain vibrations to the inner ear where they move fluid (liquid) in the cochlea that stimulates nerve endings. cochlea The nerves signal to our brain that we hear sounds.  Label the Ear Let's practice labeling the parts of the ear: eardrum s F icle middle ear cochlea cochlea G oss inner ear ossicles outer ear ear canal auditory H auditory nerves E eardrum nerves ear canalD outer ear A middle B ear Cinner ear  Hearing Damage Damaging your hearing is very bad because your ear muscles and bones do not regenerate (regrow). If you damage your ears you can go deaf. Risks to hearing include: Listening to loud music (especially in earphones). Improper maintenance and cleaning. Sound pollution (airplanes, building construction, traffic...). How Old Are Your Ears? How Sound is Used  Uses of Waves Invisible waves can be used to detect many things. Devices like sonar, radar and ultrasound produce these waves Sonar Ultrasound Radar  Sonar (SOund Navigation And Ranging) Sonar uses echos of sound waves to detect objects and measure distances under water. Sonar uses frequencies that humans cannot detect, from 20,000 - 10,000,000 Hz. Animals like dolphins, and some whales and bats, use sonar to hunt and navigate. Humans use sonar on boats to find submarines and explore the ocean.  Radar (RAdio Detection And Ranging) Radar uses echos of radio waves to detect objects, measuring the objects speed, distance and location. Radar uses extremely high frequencies, from 3,000,000 - 300 billion Hz. Radar uses electromagnetic waves to detect objects. Used to detect aircraft, ships, spacecraft, missiles, vehicles, and the weather.  Ultrasound Ultrasound scans use high-frequency sound waves to make an image of the inside of a person body. The transducer sends small pulses of high-frequency (inaudible) sound waves into the body, and records the echoing waves. The echoes can be used to Transducer make an image of what is happening inside the body. How Animals Use Sound  How Animals Hear Humans can only hear 20 - 20,000Hz, but many animals hear a different range of frequencies. Low frequencies are called infrasonic sounds. High frequencies are called ultrasonic sounds.  Infrasonic Sound Infrasonic sound waves have a frequency less than 20 Hz. This means the human ear cannot hear them. Infrasonic sound waves can travel very long distances, helping animals to communicate from far away. Examples of infrasonic animals: elephants, rhinos, whales, octopus, fish... Even though we can't hear them, we sometimes feel slow vibrations from infrasonic sound waves (e.g. earthquakes).  Ultrasonic Sound Ultrasonic sound waves have a frequency above 20,000 Hz. The human ear cannot hear them. Some animals use ultrasonic waves to navigate and find food (using echolocation) and to communicate. Examples of ultrasonic animals: dolphins, bats, frog, mice, moths... Ultrasonic waves are used by humans in ultrasound scans and for some medical treatments.  Ultrasonic VS Infrasonic Can you guess which animals are ultrasonic and infrasonic? 5 7 1 3 2 8 9 4 6  How Animals Hear Elephants Elephants have excellent hearing. They use frequencies from 14/16 - 12,000 Hz. Use infrasonic sound waves to communicate over long- distances. Can hear vibrations through their feet. How Animals Hear Bats Bats use echolocation to navigate and find food in the dark. They emit sound waves with their mouth and nose and listen for the echoes that bounce off objects. They use frequencies from 30,000 - 120,000 Hz.  How Animals Hear Dolphins Dolphins use echolocation to navigate and find food. They emit sound and use sonar to listen to the echos. They can also communicate over long distance using ultrasonic sound waves. They use frequencies from 75 - 150,000 Hz.  Textbook Practice Exploring Science Physics Textbook Pages 62 - 63 complete questions 1, 2, 4, 5, 6  Talking, laughing, shouting, clapping, sighing, etc To communicate to others, including warnings and threats, show dominance, and attract a mate.  So that the bat’s do not get confused when hunting. Two echoes from a single pulse indicates the echoes were reflected from objects that are not equidistant apart. For example, sea floor and a school of fish a) Tiger moths can confuse bats that use echolocation. b) Using transducers to record and produce ultrasounds. Review Quiz  Review Animals that use echolocation are _______ and _________. A. Bats B. Dolphins C. Snakes D. Bats and Dolphins  Review Which is NOT an example of a transducer? A. Microphone B. Speaker C. Heat D. Fan  Review What does SONAR stand for? A. Sound Navigation and Ranging B. Radio Detection and Ranging  Review Humans can hear between what frequencies? A. 10 to 10,000 Hz B. 20 to 20,000 Hz C. 30 to 30,000 Hz D. 40 to 40,000 Hz  Review Infrasonic sound waves have a frequency less than _________. A. 20 Hz B. 30 Hz C. 40 Hz D. 50 Hz  Review Ultrasonic sound waves have a frequency above __________. A. 200 Hz B. 2,000 Hz C. 20,000 Hz D. 200,000 Hz  Paper cup telephone Make a paper cup telephone using: - Paper cups - Paper clip - String  Think-Pair-Share How does the sound travel from one cup to the other? Why doesn’t it work if the strings are loose? How does the paper clip help in transferring the sound? What did we do today? 1. Describe how moving vibrations form a wave. 2. Learn how animals use ears to detect sound. 3. Understand how a microphone converts sound into electrical signals. 4. How sound is used.  Next week: We will study Lights I Bring your Physics textbook. End of Class