Physics 1240: Sound and Music Scott Parker 1/31/06. Today: Sound sources, resonance, nature of sound waves (begin wave motion)
|
|
- Lydia Wilkins
- 6 years ago
- Views:
Transcription
1 Physics 1240: Sound and Music Scott Parker 1/31/06 Today: Sound sources, resonance, nature of sound waves (begin wave motion) Next Time: Wave motion Outline Last time: Sound sources (string, reed, brass, voice, flute-type) Resonance (vibrations) Nature of sound waves Bit depth, sampling rate CD quality is 16-bit bit depth with a 44,100 Hz sampling rate CD quality requires so much data per second: 44,100 samples/sec x 2 channels x 16 bits x 1 byte/8 bits = 176,400 bytes/sec Dynamic range is the range of sound levels possible. Nyquist frequency = sampling rate / 2 The Nyquist frequency is an upper bounds on the frequencies a given sample can resolve. Musical Sound Sources Bowed String Bowing a string involves a stick-slip action where most of the cycle the string is being pulled on by the horsehairs of the bow, then a shorter part of the cycle the string slips and moves freely. This stick-slip action resonates with the frequency of oscillation of the string. Once the string begins to slip it can move fairly freely until the bow motion begins again to move with the string at the same rate. This is due to the fact that dynamic friction is less than static friction. The wheel spinning phenomena (once your wheels start slipping you loose control). Plucked or hammered strings really require the understanding of waves propagation, so we ll wait until later to discuss plucked/hammered strings. Reed Instruments: (Clarinet, Oboe, Saxophone) The reed vibrates in resonance with the 1
2 natural modes of the attached tube. The vibrating reed causes pressure pulses at rate in resonance with the tube. When the reed swings open the pressure is a maximum and the source of the pressure is the instrumentalist blowing into the mouthpiece. Then the reed swings closed and the pressure is a minimum, again in resonance with the natural modes in the tube. If you disconnect the mouthpiece it vibrates at quite a higher frequency and the frequency is sensitive to embouchure pressure on the reed. When you connect it to the instrument, you lock in on particular frequencies and it is very clear there is feedback controlling the oscillations of the reed between the reed and resonant cavity. Brass Instruments: The buzzing lips in the mouthpiece plays the role of the reed. The lips are more massive than the reed and the instrumentalist has a little more control over what frequencies are excited. This can be shown by comparing what a brass player can do with his mouthpiece versus the control a woodwind player has over only the mouthpiece. When the lips separate, a puff of air or pressure maximum sent into the horn and when the lips close a pressure minimum. It is the feedback of these oscillations with the pressure anti-node that allows the horn player to play particular tones. The brass mouthpiece/lips, like the reed behaves acoustically like a closed end. A horn without a bell will have overtones which are odd integer multiples of the fundamental (pipe closed at one end). Vocal Folds: The vocal tract is an open cavity including the nasal cavity, mouth cavity, pharynx and larynx. It ends at the vocal folds, which are made of soft skin-like tissue. The voice is like other wind instruments. There is a sound generating device and a resonant cavity. Air is forced from the lungs up through the trachea. The air stream passes through the vocal cords, which vibrate. The sound generation mechanism for the human voice is very similar to brass player's lips buzzing in a mouthpiece. The vocal folds are about 2 cm long. Frequency depends on the tension supplied by small muscles attached to the vocal folds and supporting cartilage. The Frequency range of vocal cord vibrations is approximately Hz for men and approximately Hz for women. There is an important physical effect called the Bernoulli's effect, which says that when a fluid speeds up, the pressure drops. This makes sense since if a small volume of fluid increases in speed something must be pushing on it so there must be a force on the fluid element, hence a pressure drop. The Bernoulli effect is important in the vocal tract because air flows faster through the folds causing a pressure drop and hence a force pulling the folds together. When, the folds come together, the flow is blocked and the air pressure from the lungs then pushes them apart. This is a simple explanation for how the vocal folds vibrate (especially for large amplitude vibrations of the vocal folds). Flute-type sound source: A jet of air is unstable and wants to mix and equilibrate with the background are. Take, for example, air blown through a straw. The air jet flowing out of the straw will be unstable and will begin to wobble and form a wavelike structure moving with the flow of the jet stream. Eventually, swirls are generated, then turbulence, then farther away from the end of the straw (beginning of the jet stream) there is little left to tell there was a jet stream to begin with. These wobbles of the air stream air the origin of flute-type sound sources or so-called "edge tones". An air stream is blown at a sharp edge. This produces the sound. The stream oscillates above and below the edge. Flutes, 2
3 flue organ pipes, recorders, whistles, all work using the same principle. Like with the reed (and brass instruments), the oscillating air stream couples with the resonant modes in the tube. However, opposite to the reed, the edge tone does not create pressure minimums and maximums, but rather flow minimums and maximums. When the air jet flows into the pipe the flow is a maximum or inward, when the flow goes outside the pipe the flow in the pipe is a minimum or outward. Therefore, the edge tone behaves as an open end of a pipe. In reality, there is higher pressure near the edge tone source and tuning is necessary to make the flute harmonic. This is done by tapering the pipe slightly near the embouchure hole. This part of the flute is called the head joint. To a good first approximation, you can estimate frequencies of the overtones assuming a flute is a pipe open at both ends. Resonance Resonance is driving an oscillator at its natural frequency of vibration. The classic example is the swing set. You give the child riding the swing little pushes at exactly the right time and he goes a little higher each time. This is driving the swing/child system at it s natural frequency of oscillation. Which is to a very good approximation a simple pendulum. When we bow a string, we are driving the string at it s natural frequencies. The slip-grip mechanism gives very small nudges to the string, but eventually the string oscillates quite a bit. Likewise, when a trombonist buzzes into the trombone with his mouthpiece. The natural modes of vibration of the air column in the horn are driven at their natural frequency. Sound Waves Air is what is called a compressible fluid. It is spongy, you can smash it, then let it expand back. If you push on it, it decreases in volume. For example, when you pump air into your bicycle tire, air reduces in volume and increases in pressure. Alternately, if it is allowed to expand it will. E.g. when a balloon expands when connected to a high pressure source. Sound waves are small compressions and expansions (rarefactions) of air. Convincing you that sound is simply pressure disturbances propagating from a source to the listener will not be easy. 1) We cannot see the air around us, that is, the medium of sound waves. If we can't see the medium how are we going to see the waves which propagate within it? 2) Sound produces pressure fluctuations that are one-millionth of the background of the air pressure. What is pressure anyway? Pressure is the amount of force applied per unit area. p = F / A Newtons/m 2 or Pascals (Pa). 3
4 Background air pressure is 10 5 N/ m 2. The background air pressure is a lot. We are buried beneath a sea of air, the earth's atmosphere. Why is the background air pressure so huge? Well, you can think of earth as a giant spherical fish tank, and we have a 50 km or so of air on top of us pressing down. Air weighs something. A lot less than water, but the atmosphere is pretty high, so it weighs a lot! I've drawn a 1m x 1m square on the board for perspective. 4.5 N= 1 lb (you do not need to know this specific fact). If we took a 100,000 N weight (22,000 lb) and spread it uniformly of the 1m x 1m surface (say put it on a VERY STRONG piece of plywood). This would be 10 5 N/ m 2, or equivalent to atmospheric pressure. This is a heck of a lot of weight or force, and pressure! A 1000 N person (220 lbs) standing on this square piece of plywood would only exert 1000 N/m 2! Or, only 1% of atmospheric air pressure! It is important to understand that in p=f/a, the area plays an equal role. A woman can do a lot of damage to hardwood floor when wearing heels with a very small surface area, e.g. 2 cm 2 (0.0002m 2 ). Your eardrum is very small (0.3cm), so very small forces are involved in hearing (nature has miniaturized your ear's components to save space for other important things). Sound waves of musical interest have an amplitude of 0.01 to 1 N/ m 2. That is the pressure fluctuates between say: 100, N/m 2 to 100,000-1 N/m 2 We will talk more about the amplitude, intensity and level of sound waves, in a later chapter. However, this is a very small change in pressure. How many percent would this be? % And, this would be for a loud sound! This is one of the reasons it is hard to observe sound waves directly. One important aspect of physical nature (or physics) is the similarities or strong analogies between vastly different phenomena. Wave motion is such an example. Sound waves, water waves, radio waves, light waves, they all follow very similar patterns and rules. A personal example in my own research in the area of plasma physics. Waves in space that accelerate particles to high energies and cause the aurora are virtually identical (at least from a theoretical point of view) as the waves that cause heat to escape in a magnetic bottle, and keep us from harnessing fusion energy, the energy generated by stars! 4
5 Experiment: Slinky waves We study waves on a coiled spring because we can more clearly see what is going on. The longitudinal (or compressional) waves we generate here, are very similar to sound waves. The pulse moves at a fixed speed (what we call propagates). Generally speaking, there are two types (or classes) of waves. 1) Transverse waves: motion of the medium is perpendicular to the direction of propagation of the wave. Light waves, radio waves, all electromagnetic waves, water waves, waves on a string. 2) Longitudinal waves: the motion of the medium is along the direction of propagation. Sound waves, earth quakes, all acoustic waves regardless of the medium (e.g. sound waves propagating through water, steel, etc.) Sound Speed Giving a sudden pulse on the slinky, is like hitting a drum or the bang of a fire cracker. Except for sound waves, the sound expands as a spherical shell. Really, it is much more complicated than that because neglecting there are floors and walls that reflect the sound. It would expand like a sphere if we climbed a tall pole and hit a drum, but that is not typical behavior. Anyway, the pulse propagates with a fixed speed, the speed of sound. v = 344 m/s = 770 mph All sound waves propagate at this speed regardless of pitch (or frequency). The finite speed of sound is very important in music. For example, speakers not aligned at the stage, even a few feet, will give the listener an uneasy feeling (in the high frequency range). Sound travels about 1 foot in a millisecond. The speed of sound increases slightly with temperature (0.6 m/s per degree Centigrade). 344 m/s is at 20 degrees C. Propagation of sound waves through liquids and solids is typically much faster, e.g. water v = 1500m/s steel: v = 6000 m/s The speed of an electronic signal is the speed of light or 3x10 8 m/s, which for audio purposes is instantaneous. v = d / t 5
6 Example problem: How long does it take a sound to travel 34.4 m? (approximately 113 ft, or roughly the distance from the chalk board to back of the class) t = d / v t = 34.4 / 344 = 0.1 sec 0.1 sec is very noticeable sec or 10 milliseconds is where delays become very noticeable. The is a simple fix for live performances, as done here, is to put the speaker system right on stage. Through experience, a listener expects a delay consistent with the distance from the source. Real problems occur when the direct sound from the source is delayed relative to a sound coming from a speaker. A good place to hear this problem is a sports arena, like the Pepsi Center. The speed of sound plays an important role in architectural acoustics and sound reenforcement. 6
Sound & Music. how musical notes are produced and perceived. calculate the frequency of the pitch produced by a string or pipe
Add Important Sound & Music Page: 53 NGSS Standards: N/A Sound & Music MA Curriculum Frameworks (2006): N/A AP Physics Learning Objectives: 6.D.3., 6.D.3.2, 6.D.3.3, 6.D.3.4, 6.D.4., 6.D.4.2, 6.D.5. Knowledge/Understanding
More informationPHYSICS 102N Spring Week 6 Oscillations, Waves, Sound and Music
PHYSICS 102N Spring 2009 Week 6 Oscillations, Waves, Sound and Music Oscillations Any process that repeats itself after fixed time period T Examples: Pendulum, spring and weight, orbits, vibrations (musical
More informationPreview. Sound Section 1. Section 1 Sound Waves. Section 2 Sound Intensity and Resonance. Section 3 Harmonics
Sound Section 1 Preview Section 1 Sound Waves Section 2 Sound Intensity and Resonance Section 3 Harmonics Sound Section 1 TEKS The student is expected to: 7A examine and describe oscillatory motion and
More informationPHY-2464 Physical Basis of Music
Physical Basis of Music Presentation 19 Characteristic Sound (Timbre) of Wind Instruments Adapted from Sam Matteson s Unit 3 Session 30 and Unit 1 Session 10 Sam Trickey Mar. 15, 2005 REMINDERS: Brass
More informationSound Interference and Resonance: Standing Waves in Air Columns
Sound Interference and Resonance: Standing Waves in Air Columns Bởi: OpenStaxCollege Some types of headphones use the phenomena of constructive and destructive interference to cancel out outside noises.
More informationCopyright 2009 Pearson Education, Inc.
Chapter 16 Sound 16-1 Characteristics of Sound Sound can travel through h any kind of matter, but not through a vacuum. The speed of sound is different in different materials; in general, it is slowest
More informationWaves and Sound. AP Physics 1
Waves and Sound AP Physics 1 What is a wave A WAVE is a vibration or disturbance in space. A MEDIUM is the substance that all SOUND WAVES travel through and need to have in order to move. Classes of waves
More informationDemonstrate understanding of wave systems. Demonstrate understanding of wave systems. Achievement Achievement with Merit Achievement with Excellence
Demonstrate understanding of wave systems Subject Reference Physics 3.3 Title Demonstrate understanding of wave systems Level 3 Credits 4 Assessment External This achievement standard involves demonstrating
More informationNo Brain Too Small PHYSICS
WAVES: STANDING WAVES QUESTIONS No Brain Too Small PHYSICS PAN FLUTES (2016;1) Assume the speed of sound in air is 343 m s -1. A pan flute is a musical instrument made of a set of pipes that are closed
More informationSUGGESTED ACTIVITIES
SUGGESTED ACTIVITIES (Sound) From Invitations to Science Inquiry 2 nd Edition by Tik L. Liem: Activity Page Number Concept The Coat Hanger Church Bell 305 Sound Travels The Soda Can Telephone 304 Sound
More informationChapter 18. Superposition and Standing Waves
Chapter 18 Superposition and Standing Waves Particles & Waves Spread Out in Space: NONLOCAL Superposition: Waves add in space and show interference. Do not have mass or Momentum Waves transmit energy.
More informationChapter 05: Wave Motions and Sound
Chapter 05: Wave Motions and Sound Section 5.1: Forces and Elastic Materials Elasticity It's not just the stretch, it's the snap back An elastic material will return to its original shape when stretched
More informationChapter 15 Supplement HPS. Harmonic Motion
Chapter 15 Supplement HPS Harmonic Motion Motion Linear Moves from one place to another Harmonic Motion that repeats over and over again Examples time, speed, acceleration Examples Pendulum Swing Pedaling
More informationSound, acoustics Slides based on: Rossing, The science of sound, 1990.
Sound, acoustics Slides based on: Rossing, The science of sound, 1990. Acoustics 1 1 Introduction Acoustics 2! The word acoustics refers to the science of sound and is a subcategory of physics! Room acoustics
More informationA Look at Un-Electronic Musical Instruments
A Look at Un-Electronic Musical Instruments A little later in the course we will be looking at the problem of how to construct an electrical model, or analog, of an acoustical musical instrument. To prepare
More informationChapter 14, Sound. 1. When a sine wave is used to represent a sound wave, the crest corresponds to:
CHAPTER 14 1. When a sine wave is used to represent a sound wave, the crest corresponds to: a. rarefaction b. condensation c. point where molecules vibrate at a right angle to the direction of wave travel
More informationCopyright 2010 Pearson Education, Inc.
14-7 Superposition and Interference Waves of small amplitude traveling through the same medium combine, or superpose, by simple addition. 14-7 Superposition and Interference If two pulses combine to give
More informationWarm-Up. Think of three examples of waves. What do waves have in common? What, if anything, do waves carry from one place to another?
Warm-Up Think of three examples of waves. What do waves have in common? What, if anything, do waves carry from one place to another? WAVES Physics Waves If you can only remember one thing Waves transmit
More informationSound All sound begins with a vibrating object Ex. Vibrating tuning fork Vibrating prong sets molecules near it in motion
Sound All sound begins with a vibrating object Ex. Vibrating tuning fork Vibrating prong sets molecules near it in motion As prong swings right, air molecules in front of the movement are forced closer
More informationCHAPTER 12 SOUND ass/sound/soundtoc. html. Characteristics of Sound
CHAPTER 12 SOUND http://www.physicsclassroom.com/cl ass/sound/soundtoc. html Characteristics of Sound Intensity of Sound: Decibels The Ear and Its Response; Loudness Sources of Sound: Vibrating Strings
More informationResonance and resonators
Resonance and resonators Dr. Christian DiCanio cdicanio@buffalo.edu University at Buffalo 10/13/15 DiCanio (UB) Resonance 10/13/15 1 / 27 Harmonics Harmonics and Resonance An example... Suppose you are
More informationTest Review # 7. Physics R: Form TR7.17A. v C M = mach number M = C v = speed relative to the medium v sound C v sound = speed of sound in the medium
Physics R: Form TR7.17A TEST 7 REVIEW Name Date Period Test Review # 7 Frequency and pitch. The higher the frequency of a sound wave is, the higher the pitch is. Humans can detect sounds with frequencies
More informationChapter 21 Musical Instruments
Lecture 22 Chapter 21 Musical Instruments CR/NC Deadline Oct. 19 Musical Instruments Now that we understand some of the physics of sound, let s analyze how musical sound is produced by different types
More informationA mechanical wave is a disturbance which propagates through a medium with little or no net displacement of the particles of the medium.
Waves and Sound Mechanical Wave A mechanical wave is a disturbance which propagates through a medium with little or no net displacement of the particles of the medium. Water Waves Wave Pulse People Wave
More informationg L f = 1 2π Agenda Chapter 14, Problem 24 Intensity of Sound Waves Various Intensities of Sound Intensity Level of Sound Waves
Agenda Today: HW #1 Quiz, power and energy in waves and decibel scale Thursday: Doppler effect, more superposition & interference, closed vs. open tubes Chapter 14, Problem 4 A 00 g ball is tied to a string.
More informationPhysics I Notes: Chapter 13 Sound
Physics I Notes: Chapter 13 Sound I. Properties of Sound A. Sound is the only thing that one can hear! Where do sounds come from?? Sounds are produced by VIBRATING or OSCILLATING OBJECTS! Sound is a longitudinal
More informationExam 3--PHYS 151--Chapter 4--S14
Class: Date: Exam 3--PHYS 151--Chapter 4--S14 Multiple Choice Identify the choice that best completes the statement or answers the question. 1. Which of these statements is not true for a longitudinal
More informationMusic. Sound Part II
Music Sound Part II What is the study of sound called? Acoustics What is the difference between music and noise? Music: Sound that follows a regular pattern; a mixture of frequencies which have a clear
More informationChapter PREPTEST: SHM & WAVE PROPERTIES
2 4 Chapter 13-14 PREPTEST: SHM & WAVE PROPERTIES Multiple Choice Identify the choice that best completes the statement or answers the question. 1. A load of 45 N attached to a spring that is hanging vertically
More informationSOUND & MUSIC. Sound & Music 1
SOUND & MUSIC Sound is produced by a rapid variation in the average density or pressure of air molecules. We perceive sound as these pressure changes cause our eardrums to vibrate. Sound waves are produced
More informationSECTION A Waves and Sound
AP Physics Multiple Choice Practice Waves and Optics SECTION A Waves and Sound 2. A string is firmly attached at both ends. When a frequency of 60 Hz is applied, the string vibrates in the standing wave
More informationName: Date: Period: Physics: Study guide concepts for waves and sound
Name: Date: Period: Physics: Study guide concepts for waves and sound Waves Sound What is a wave? Identify parts of a wave (amplitude, frequency, period, wavelength) Constructive and destructive interference
More informationABC Math Student Copy
Page 1 of 17 Physics Week 9(Sem. 2) Name Chapter Summary Waves and Sound Cont d 2 Principle of Linear Superposition Sound is a pressure wave. Often two or more sound waves are present at the same place
More informationSound and Resonance Page 1 Sound and Resonance List of Materials Needed Sample Curriculum Sound Information
Sound and Resonance Page 1 Sound and Resonance Sound Words 2 Sound and Vibrating Objects 3 Soda Bottle Symphonies 5 Hooey Stick Mystery 7 The Tacoma Narrows Bridge 9 Springs and Waves Demonstration 10
More informationWaves and Sound Practice Test 43 points total Free- response part: [27 points]
Name Waves and Sound Practice Test 43 points total Free- response part: [27 points] 1. To demonstrate standing waves, one end of a string is attached to a tuning fork with frequency 120 Hz. The other end
More informationSound. Introduction. Key concepts of sound
Sound Introduction This topic explores the key concepts of sound as they relate to: the nature of sound the transmission of sound resonance the speed of sound sound and hearing. Key concepts of sound The
More informationWaves & Interference
Waves & Interference I. Definitions and Types II. Parameters and Equations III. Sound IV. Graphs of Waves V. Interference - superposition - standing waves The student will be able to: HW: 1 Define, apply,
More informationCh17. The Principle of Linear Superposition and Interference Phenomena. The Principle of Linear Superposition
Ch17. The Principle of Linear Superposition and Interference Phenomena The Principle of Linear Superposition 1 THE PRINCIPLE OF LINEAR SUPERPOSITION When two or more waves are present simultaneously at
More informationWorksheet 15.2 Musical Instruments
Worksheet 15.2 Musical Instruments 1. You and your group stretch a spring 12 feet across the floor and you produce a standing wave that has a node at each end and one antinode in the center. Sketch this
More informationMusical instruments: strings and pipes
Musical instruments: strings and pipes Physics 211 Syracuse University, Physics 211 Spring 2017 Walter Freeman April 24, 2017 W. Freeman Musical instruments: strings and pipes April 24, 2017 1 / 11 Announcements
More informationChapter 12. Preview. Objectives The Production of Sound Waves Frequency of Sound Waves The Doppler Effect. Section 1 Sound Waves
Section 1 Sound Waves Preview Objectives The Production of Sound Waves Frequency of Sound Waves The Doppler Effect Section 1 Sound Waves Objectives Explain how sound waves are produced. Relate frequency
More information3A: PROPERTIES OF WAVES
3A: PROPERTIES OF WAVES Int roduct ion Your ear is complicated device that is designed to detect variations in the pressure of the air at your eardrum. The reason this is so useful is that disturbances
More informationToday: Finish Chapter 15 (Temp, Heat, Expansion) Chapter 19 (Vibrations and Waves)
Today: Finish Chapter 15 (Temp, Heat, Expansion) Chapter 19 (Vibrations and Waves) Vibrations Some Preliminaries Vibration = oscillation = anything that has a back-and-forth to it Eg. Draw a pen back and
More informationSource-Filter Theory 1
Source-Filter Theory 1 Vocal tract as sound production device Sound production by the vocal tract can be understood by analogy to a wind or brass instrument. sound generation sound shaping (or filtering)
More informationWaves and Modes. Part I. Standing Waves. A. Modes
Part I. Standing Waves Waves and Modes Whenever a wave (sound, heat, light,...) is confined to a finite region of space (string, pipe, cavity,... ), something remarkable happens the space fills up with
More informationThe Physics of Musical Instruments
Neville H. Fletcher Thomas D. Rossing The Physics of Musical Instruments Second Edition With 485 Illustrations Springer Contents Preface Preface to the First Edition v vii I. Vibrating Systems 1. Free
More informationLecture Presentation Chapter 16 Superposition and Standing Waves
Lecture Presentation Chapter 16 Superposition and Standing Waves Suggested Videos for Chapter 16 Prelecture Videos Constructive and Destructive Interference Standing Waves Physics of Your Vocal System
More informationChapter 16. Waves and Sound
Chapter 16 Waves and Sound 16.1 The Nature of Waves 1. A wave is a traveling disturbance. 2. A wave carries energy from place to place. 1 16.1 The Nature of Waves Transverse Wave 16.1 The Nature of Waves
More informationInterference & Superposition. Creating Complex Wave Forms
Interference & Superposition Creating Complex Wave Forms Waves & Interference I. Definitions and Types II. Parameters and Equations III. Sound IV. Graphs of Waves V. Interference - superposition - standing
More informationVibrations and Waves. Properties of Vibrations
Vibrations and Waves For a vibration to occur an object must repeat a movement during a time interval. A wave is a disturbance that extends from one place to another through space. Light and sound are
More informationThe Nature of Sound. What produces sound?
1 The Nature of Sound What produces sound? Every sound is produced by an object that vibrates. For example, your friends voices are produced by the vibrations of their vocal cords, and music from a carousel
More informationSECTION A Waves and Sound
AP Physics Multiple Choice Practice Waves and Optics SECTION A Waves and Sound 1. Which of the following statements about the speed of waves on a string are true? I. The speed depends on the tension in
More informationMusic: Sound that follows a regular pattern; a mixture of frequencies which have a clear mathematical relationship between them.
The Sound of Music Music: Sound that follows a regular pattern; a mixture of frequencies which have a clear mathematical relationship between them. How is music formed? By STANDING WAVES Formed due to
More informationSound. Production of Sound
Sound Production o Sound Sound is produced by a vibrating object. A loudspeaker has a membrane or diaphragm that is made to vibrate by electrical currents. Musical instruments such as gongs or cymbals
More informationCh 26: Sound Review 2 Short Answers 1. What is the source of all sound?
Ch 26: Sound Review 2 Short Answers 1. What is the source of all sound? 2. How does a sound wave travel through air? 3. What media transmit sound? 4. What determines the speed of sound in a medium? 5.
More informationAP Homework (Q2) Does the sound intensity level obey the inverse-square law? Why?
AP Homework 11.1 Loudness & Intensity (Q1) Which has a more direct influence on the loudness of a sound wave: the displacement amplitude or the pressure amplitude? Explain your reasoning. (Q2) Does the
More informationPHYS102 Previous Exam Problems. Sound Waves. If the speed of sound in air is not given in the problem, take it as 343 m/s.
PHYS102 Previous Exam Problems CHAPTER 17 Sound Waves Sound waves Interference of sound waves Intensity & level Resonance in tubes Doppler effect If the speed of sound in air is not given in the problem,
More informationconstructive interference results when destructive interference results when two special interference patterns are the and the
Interference and Sound Last class we looked at interference and found that constructive interference results when destructive interference results when two special interference patterns are the and the
More informationIntroduction. Physics 1CL WAVES AND SOUND FALL 2009
Introduction This lab and the next are based on the physics of waves and sound. In this lab, transverse waves on a string and both transverse and longitudinal waves on a slinky are studied. To describe
More informationSound & Waves Review. Physics - Mr. Jones
Sound & Waves Review Physics - Mr. Jones Waves Types Transverse, longitudinal (compression) Characteristics Frequency, period, wavelength, amplitude, crest, trough v = f! Review: What is sound? Sound is
More information= 2n! 1 " L n. = 2n! 1 # v. = 2n! 1 " v % v = m/s + ( m/s/ C)T. f 1. = 142 Hz
Chapter 9 Review, pages 7 Knowledge 1. (b). (c) 3. (b). (d) 5. (b) 6. (d) 7. (d) 8. (b) 9. (a) 10. (c) 11. (a) 1. (c) 13. (b) 1. (b) 15. (d) 16. False. Interference does not leave a wave permanently altered.
More informationQ15.9. Monday, May 2, Pearson Education, Inc.
Q15.9 While a guitar string is vibrating, you gently touch the midpoint of the string to ensure that the string does not vibrate at that point. The lowest-frequency standing wave that could be present
More informationL 23 Vibrations and Waves [3]
L 23 Vibrations and Waves [3] resonance clocks pendulum springs harmonic motion mechanical waves sound waves golden rule for waves musical instruments The Doppler effect Doppler radar radar guns Review
More informationENGINEERing challenge workshop for science museums in the field of sound & acoustics
ENGINEERing challenge workshop for science museums in the field of sound & acoustics 1 Index Workshop ID card...3 Specific unit objectives...4 Resources...4 The workshop...5 Introduction...5 The main activity...6
More informationFinal Reg Wave and Sound Review SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.
Final Reg Wave and Sound Review SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. 1) What is the frequency of a 2.5 m wave traveling at 1400 m/s? 1) 2)
More information1. How does life depend on water? 2. Give three examples of the interactions between spheres. International School of Arts and Sciences ISAS
Grade 6 Science Summer Work International School of Arts and Sciences ISAS 2015-2016 Earth s spheres Our planet has many parts. These parts work together. Without these parts, our spinning days would be
More informationParents and Educators: use #CuriousCrew #CuriosityGuide to share what your Curious Crew learned!
Investigation: 01 Visible Sound We re used to hearing sound, but there s a way to SEE sound too. Computer with free downloaded tone generator software Sound cable Amplifier or speaker Shallow metal pan
More informationSound. DEF: A pressure variation that is transmitted through matter. Collisions are high pressure / compressions.
Sound Sound DEF: A pressure variation that is transmitted through matter. Link to pic of bell animation Collisions are high pressure / compressions. Pulls are low pressure / rarefacation. Have same properties
More informationWaves Homework. Assignment #1. Assignment #2
Waves Homework Assignment #1 Textbook: Read Section 11-7 and 11-8 Online: Waves Lesson 1a, 1b, 1c http://www.physicsclassroom.com/class/waves * problems are for all students ** problems are for honors
More informationF R O M T H E S C I E N C E L A B
FROM THE SCIENCE LAB Volume, Decibels and Forces Ultrasound The Secrets of Sound Ruben s Tube Puppets! Prokofiev wrote his first opera aged nine Each character in the story represented by a different instrument
More informationWaves Q1. MockTime.com. (c) speed of propagation = 5 (d) period π/15 Ans: (c)
Waves Q1. (a) v = 5 cm (b) λ = 18 cm (c) a = 0.04 cm (d) f = 50 Hz Q2. The velocity of sound in any gas depends upon [1988] (a) wavelength of sound only (b) density and elasticity of gas (c) intensity
More informationAcoustics: How does sound travel? Student Version
Acoustics: How does sound travel? Student Version In this lab, you will learn about where sound comes from, how it travels, and what changes the loudness of a sound or the pitch of a sound. We will do
More information1. At which position(s) will the child hear the same frequency as that heard by a stationary observer standing next to the whistle?
Name: Date: Use the following to answer question 1: The diagram shows the various positions of a child in motion on a swing. Somewhere in front of the child a stationary whistle is blowing. 1. At which
More informationHonors Physics-121B Sound and Musical Acoustics Introduction: Production of Sounds by Various Sources: Media That Transmit Sound:
Honors Physics-121B Sound and Musical Acoustics Introduction: This unit deals with the properties of longitudinal (compressional) waves traveling through various media. As these waves travel through the
More informationWaves transfer energy NOT matter Two categories of waves Mechanical Waves require a medium (matter) to transfer wave energy Electromagnetic waves no
1 Waves transfer energy NOT matter Two categories of waves Mechanical Waves require a medium (matter) to transfer wave energy Electromagnetic waves no medium required to transfer wave energy 2 Mechanical
More informationStanding Waves and Musical Instruments
OpenStax-CNX module: m12413 1 Standing Waves and Musical Instruments Catherine Schmidt-Jones This work is produced by OpenStax-CNX and licensed under the Creative Commons Attribution License 3.0 Abstract
More information26 Sound. Sound is a form of energy that spreads out through space.
Sound is a form of energy that spreads out through space. When a singer sings, the vocal chords in the singer s throat vibrate, causing adjacent air molecules to vibrate. A series of ripples in the form
More informationPHYSICS. Sound & Music
PHYSICS Sound & Music 20.1 The Origin of Sound The source of all sound waves is vibration. 20.1 The Origin of Sound The original vibration stimulates the vibration of something larger or more massive.
More informationSUMMARY. ) f s Shock wave Sonic boom UNIT. Waves transmit energy. Sound is a longitudinal mechanical wave. KEY CONCEPTS CHAPTER SUMMARY
UNIT D SUMMARY KEY CONCEPTS CHAPTER SUMMARY 9 Waves transmit energy. Crest, trough, amplitude, wavelength Longitudinal and transverse waves Cycle Period, frequency f 1_ T Universal wave equation v fλ Wave
More informationSound 05/02/2006. Lecture 10 1
What IS Sound? Sound is really tiny fluctuations of air pressure units of pressure: N/m 2 or psi (lbs/square-inch) Carried through air at 345 m/s (770 m.p.h) as compressions and rarefactions in air pressure
More information10/24/ Teilhard de Chardin French Geologist. The answer to the question is ENERGY, not MATTER!
Someday, after mastering the winds, the waves, the tides and gravity, we shall harness for God the energies of love, and then, for a second time in the history of the world, man will have discovered fire.
More informationdescribe sound as the transmission of energy via longitudinal pressure waves;
1 Sound-Detailed Study Study Design 2009 2012 Unit 4 Detailed Study: Sound describe sound as the transmission of energy via longitudinal pressure waves; analyse sound using wavelength, frequency and speed
More informationSection 1 Sound Waves. Chapter 12. Sound Waves. Copyright by Holt, Rinehart and Winston. All rights reserved.
Section 1 Sound Waves Sound Waves Section 1 Sound Waves The Production of Sound Waves, continued Sound waves are longitudinal. Section 1 Sound Waves Frequency and Pitch The frequency for sound is known
More information3) For vibrational motion, the maximum displacement from the equilibrium point is called the
WAVES & SOUND Conceptual Questions 1) The time for one cycle of a periodic process is called the 2) For a periodic process, the number of cycles per unit time is called the 3) For vibrational motion, the
More informationRarefaction Compression
::Sound:: Sound is a longitudinal wave Rarefaction Sound consists of a series of compressions and rarefactions. However, for simplicity sake, sound is usually represented as a transverse wave as exemplified
More informationReview. Top view of ripples on a pond. The golden rule for waves. The golden rule for waves. L 23 Vibrations and Waves [3] ripples
L 23 Vibrations and Waves [3] resonance clocks pendulum springs harmonic motion mechanical waves sound waves golden rule for waves musical instruments The Doppler effect Doppler radar radar guns Review
More informationChapter 9: Wave Interactions
Chapter 9: Wave Interactions Mini Investigation: Media Changes, page 15 A. In each situation, the transmitted wave keeps the orientation of the original wave while the reflected wave has the opposite orientation.
More informationì<(sk$m)=bdieha< +^-Ä-U-Ä-U
Physical Science by Timothy Sandow Genre Comprehension Skill Text Features Science Content Nonfiction Compare and Contrast Captions Labels Sound Diagram Glossary Scott Foresman Science 3.14 ì
More informationFrom Last Time Wave Properties. Doppler Effect for a moving source. Question. Shock Waves and Sonic Booms. Breaking the sound barrier.
From Last Time Wave Properties Interference: waves can superimpose constructively or destructively Two speakers can be quieter than one! Doppler effect Frequency shift (up or down) from moving source.
More informationLecture PowerPoints. Chapter 12 Physics: Principles with Applications, 7 th edition Giancoli
Lecture PowerPoints Chapter 12 Physics: Principles with Applications, 7 th edition Giancoli This work is protected by United States copyright laws and is provided solely for the use of instructors in teaching
More informationLecture 19. Superposition, interference, standing waves
ecture 19 Superposition, interference, standing waves Today s Topics: Principle of Superposition Constructive and Destructive Interference Beats Standing Waves The principle of linear superposition When
More informationSOUND. Second, the energy is transferred from the source in the form of a longitudinal sound wave.
SOUND - we can distinguish three aspects of any sound. First, there must be a source for a sound. As with any wave, the source of a sound wave is a vibrating object. Second, the energy is transferred from
More informationConcepts in Physics. Friday, November 26th 2009
1206 - Concepts in Physics Friday, November 26th 2009 Notes There is a new point on the webpage things to look at for the final exam So far you have the two midterms there More things will be posted over
More informationLecture PowerPoints. Chapter 12 Physics: Principles with Applications, 6 th edition Giancoli
Lecture PowerPoints Chapter 12 Physics: Principles with Applications, 6 th edition Giancoli 2005 Pearson Prentice Hall This work is protected by United States copyright laws and is provided solely for
More informationResonance Tube. 1 Purpose. 2 Theory. 2.1 Air As A Spring. 2.2 Traveling Sound Waves in Air
Resonance Tube Equipment Capstone, complete resonance tube (tube, piston assembly, speaker stand, piston stand, mike with adapters, channel), voltage sensor, 1.5 m leads (2), (room) thermometer, flat rubber
More informationPsychology of Language
PSYCH 150 / LIN 155 UCI COGNITIVE SCIENCES syn lab Psychology of Language Prof. Jon Sprouse 01.10.13: The Mental Representation of Speech Sounds 1 A logical organization For clarity s sake, we ll organize
More informationChapter 7. Waves and Sound
Chapter 7 Waves and Sound What is wave? A wave is a disturbance that propagates from one place to another. Or simply, it carries energy from place to place. The easiest type of wave to visualize is a transverse
More information16.3 Standing Waves on a String.notebook February 16, 2018
Section 16.3 Standing Waves on a String A wave pulse traveling along a string attached to a wall will be reflected when it reaches the wall, or the boundary. All of the wave s energy is reflected; hence
More informationTEAK Sound and Music
Sound and Music 2 Instructor Preparation Guide Important Terms Wave A wave is a disturbance or vibration that travels through space. The waves move through the air, or another material, until a sensor
More informationName Date Class _. Holt Science Spectrum
Holt Science Spectrum Holt, Rinehart and Winston presents the Guided Reading Audio CD Program, recorded to accompany Holt Science Spectrum. Please open your book to the chapter titled Sound and Light.
More information