The Doppler Effect PHY238Y Lecture 13 References:

Slides:

Advertisements

Similar presentations

Sound Notes. The Nature of Sound Sound travels in longitudinal waves consisting of oscillating compressions and rarefactions through the air. Sound travels.

Advertisements

A sound is a wave and frequency determines pitch

Physics 12 Source: Giancoli Chapters 11 and 12

UNIT 7 Waves, Vibrations, and

SOUND WAVES Sound is a longitudinal wave produced by a vibration that travels away from the source through solids, liquids, or gases, but not through a.

Phys 250 Ch15 p1 Chapter 15: Waves and Sound Example: pulse on a string speed of pulse = wave speed = v depends upon tension T and inertia (mass per length.

Sound and Hearing. Sound Waves Sound waves are mechanical and longitudinal waves What does this tell you about sound waves? Sound waves need a material.

PHY238Y Lecture 6 Energy and power of a transverse wave in a string References: Haliday, Resnick, Walker: Fundamentals of Physics, 6 th ed., Wiley 2003,

Chapter 11 Sound.

Doppler Effect.

Phy 202: General Physics II Ch 16: Waves & Sound Lecture Notes.

Lecture 1 – Waves & Sound c) Sound.

Phy 212: General Physics II

صدق الله العظيم الاسراء اية 58. By Dr. Abdel Aziz M. Hussein Lecturer of Physiology Member of American Society of Physiology.

© 2011 The McGraw-Hill Companies, Inc. Instructor name Class Title, Term/Semester, Year Institution Introductory Psychology Concepts Hearing.

Chapter 12 Sound.

Chapter 12 Sound Characteristics of Sound Sound can travel through any kind of matter, but not through a vacuum. The speed of sound is different.

Chapter 14 Sound. Sound is a pressure wave caused by vibrating sources. The pressure in the medium carrying the sound wave increases and decreases as.

Chapter 14 Sound. Characteristics of sound 2 A special and important type of mechanical wave Speed of sound: Loudness: related to the energy of sound.

Chapter 12 Sound Hr Physics. Sound  Vibrations in matter. No one need be around to hear it.  Composed of Compressions & Rarefactions.  Compressions.

PHY238Y Lecture 8  Sound waves  The speed of sound  Traveling sound waves  Intensity and sound level References: Haliday, Resnick, Walker: Fundamentals.

Sound Carl Wozniak Northern Michigan University. Some sound facts?  Sound is a mechanical wave which is created by vibrating objects and propagated through.

PHY238Y Lecture 11 The human ear: amplification of the outer/inner ear Acoustic impedance. Physics of hearing (III) Protection mechanisms of the human.

24.3 Sound  Sound is a traveling oscillation of atoms or pressure.  When they are pushed by the vibrations, it creates a layer of higher pressure which.

Perception: Hearing Sound: Amplitude – loudness (decibels)

IPC Notes Sound. The Nature of Sound Sound waves are caused by vibrations of molecules that travel in the form of compressional waves.

Mechanical Waves vs. Electromagnetic Waves Mechanical – require a medium to travel –ex: water, sound, rope Electromagnetic – can travel through space.

Sound. Characteristics of Sound Intensity of Sound: Decibels The Ear and Its Response; Loudness Interference of Sound Waves; Beats Doppler Effect Topics.

Chapter 15 Sound What is Sound? a pressure disturbance

Project Boomilever  wooden tower designed to hold maximum weight Electric vehicle  electric-propelled car designed to go a specific distance Sounds of.

SOUND Entry # 10. Sound: –the vibration of particles that travel in a longitudinal wave. –a mechanical wave which travels through a medium When that disturbance.

Objectives Demonstrate knowledge of the nature of sound waves and the properties sound shares with other waves. Solve problems relating frequency, wavelength,

PHY238Y Lecture 10 The human ear (outer and middle) Physics of hearing (II) References: Haliday, Resnick, Walker: Fundamentals of Physics, 6 th ed. 2003,

PHY238Y Lecture 5 Waves (general discussion) Transverse and longitudinal waves Properties of waves: - Amplitude and phase - Wavelength and angular number.

 Mechanical wave- a disturbance in matter that carries energy from one place to another  Require a medium to travel through ◦ A medium can be a.

Chapter 12 Sound Characteristics of Sound Sound can travel through any kind of matter, but not through a vacuum. The speed of sound is different.

Sound Chapter 15. Sound Waves Sound is a longitudinal wave. (medium displaces parallel to direction of the wave) Sound is a longitudinal wave. (medium.

Sound. Review Sound is a mechanical wave Sound is a mechanical wave

What is Sound?? n “If a tree falls in the forest and no one is there to hear it, does it make a sound?” n There are 2 ways to answer this: n Objectively.

SOUND Nature and Properties. MAIN IDEA Sound waves are longitudinal waves that travel only through matter.

CHAPTER 13 Sound.

Physics of Music (PHYSICS 198)

Chapter 16 answers to study guide

Sound Holt Chapter 12.

17.4 Sound and Hearing.

AP Physics Section 12-1 to 12-3 Sound Properties.

Unit 6 Chapter 18 & 19 Sound and Light

Physics of Sound (continued from Lecture 8) Physics of hearing (I)

Waves and Wave Properties

Doppler Effect (continued from Lecture 13 - slides 7-12) Ultrasound

Ch Waves & Sound II. The Nature of Sound Speed of Sound

Chapter 12 Sound.

Ch Waves & Sound II. The Nature of Sound Speed of Sound

PHSC 1013: Physical Science Waves

Waves and Wave Properties

Ch Waves & Sound II. The Nature of Sound Speed of Sound

Ch Waves & Sound II. The Nature of Sound Speed of Sound

Chapter 12, Section 1 The Nature of Sound.

Chapter 12 Sound © 2014 Pearson Education, Inc..

Ch Waves & Sound II. The Nature of Sound Speed of Sound

Ch Waves & Sound II. The Nature of Sound Speed of Sound

Waves & Sound The Nature of Sound Speed of Sound Human hearing

Chapter 15 Notes Sound.

Presentation transcript:

The Doppler Effect PHY238Y Lecture 13 References: Halliday, Resnick, Walker: Fundamentals of Physics, 6th ed., Wiley 2003, Chapter 18 (18.8) Hallett et al.: Physics for the life sciences, 4th ed., 2003, Ch.2 (2.7) Some of the pictures were taken from Hyper Physics: http://hyperphysics.phy-astr.gsu.edu/hbase/sound/soucon.html#soucon Thanks to dr. Rod Nave for the permission to use the above resource

Example (Ear amplifier) PHY238Y Lecture 13 Hearing: pressure in the cochlear liquid vs. pressure on the eardrum (does human ear really amplifies sound?) Example (Ear amplifier) 1) Calculate the maximum net force on an eardrum due to a sound wave having a maximum pressure of 2* 10-3 N/m2, if the diameter of the eardrum is 0.0085m. 2) Assuming the mechanical advantage of the hammer, anvil and stirrup is 2, calculate the pressure created on the oval window (Ao = 0.03cm2) 3) Assuming the acoustic impedance of air Zair = 416 N*s/m3; and water Zwater = 1.48*106 N*s/m3, calculate the relative transmission of the oval window to sound waves (stransmitted/sincident).

PHY238Y Lecture 13 Absorption of sound: sound waves produce molecular motion in the material they propagate; Friction reduces intensity by energy dissipation. Inside a medium: The attenuation length x0 depends strongly on: frequency and the type of medium involved.

Attenuation length (mm) PHY238Y Lecture 13 Attenuation of sound waves in various media Material Frequency (Hz) Attenuation length (mm) Water 20 105 106 Muscle 4*10-2 Bone 4*10-3 3.5*106 6*10-4

PHY238Y Lecture 13 Noise; noise reduction Decrease of sound intensity: where a is the characteristic dissipation coefficient for a given medium

PHY238Y Lecture 13 Sound source is stationary, observer (detector) is moving “into the waves”

PHY238Y Lecture 13 Doppler effect for a source at rest (a) and moving (b). Observer (detector) is at rest.

PHY238Y Lecture 13 Both detector (observer) and source move Speed of sound is v Speed of the observer is v0 Speed of the source is vs

PHY238Y Lecture 13

PHY238Y Lecture 13

PHY238Y Lecture 13

? Is Doppler effect an illusion? PHY238Y Lecture 13 J.G. Neuhoff, M.K. McBeath: Am. J. Phys., Vol.65(7), 1997 found out that: Perceptual processing of frequency and intensity interact; Judgments about magnitude and direction of pitch change are influenced by changes in loudness; The intensity of a Doppler-shifted tone rises as the source approaches; loudness changes influence pitch change, so pitch is also perceived to rise ?