THE ACOUSTICS OF ROOMS

Save this PDF as:

Size: px
Start display at page:

Transcription

1 Killam 1 THE ACOUSTICS OF ROOMS Josiah Killam PHYS 193: The Physics of Music Prof. Steven Errede University of Illinois at Urbana-Champaign

2 Killam 2 For my project for The Physics of Music, I decided to research the acoustic properties of different rooms, and how rooms for specific acoustically purposes are built. These rooms include special auditoriums, whispering galleries, reverberation rooms, and anechoic chambers. These rooms are built by acoustical engineers, or acousticians, who are scientists in the field of acoustics. Acoustics, derived from the Greek word ακουστικός (akoustikos) meaning of/for hearing, is described as the science of all mechanical waves through a solid, liquid, or gas. These mechanical waves include vibration waves, sound waves, ultrasound waves, and infrasound waves. The specific branch of acoustics that are used in the design of auditoriums and the like are sound waves. So how do sound waves react in an environment like an auditorium? The intensity of sound obeys a law of physics called the inverse square law. The ISL states that the intensity of a sound is equal to the source power divided by the area of the sphere of which the point of measurement lies on the surface of, and the source is the center of (see diagram below for visual representation and equation). This is the problem acoustical engineers must face when designing an auditorium: how can you prevent the sound depreciation caused by the inverse square law? Luckily for the engineers, there

3 Killam 3 are other things that have an effect on sound waves besides the inverse square law. Three majors factors acoustical engineers use to design rooms are reflection, absorption, and reverberation. Reflection is when sound hits a solid object and bounces off of it in a different direction. It is the cause of such things like echoes, and is the reason why devices like sonar are possible. The science behind reflection is another law, called the law of reflection. This law does not only apply to sound waves, but to many other things ranging from light to the way a billiard ball bounces off of the side of the table. The law of reflection states that the angle made by the incident wave and the surface is equal to the angle made by the reflected wave and surface (shown in the figure to the left). The problem with reflection is that the reflected waves can interfere with incident waves and mess with the sound of the performance, constructively or destructively. The challenge of architectural engineers is to create a space so the waves reflected off of the walls of the auditorium constructively disturb the incident waves, producing a louder sound intensity. But when a sound wave hits the wall of an auditorium, not all of the sound is reflected. Another key factor in acoustical management is absorption. Absorption is the second part of a wave hitting a wall. Instead of bouncing back, some of the sound is absorbed through the material, causing the reflected wave to have less intensity than the incident wave. In fact, the intensity of the incident wave is equal to the intensity of the reflected wave plus the intensity of the absorbed wave. Depending on the purpose of the room being designed, acoustical engineers may want to maximize or minimize absorption. Anechoic chambers are an example of the former, while basic auditoriums are an example of the latter, both of which I will discuss in more detail further on. How well a room absorbs sound is quantified by the effective absorption area of the walls, which is calculated using the dimensions of the walls and the absorption coefficient,

4 Killam 4 which is a constant that differs between materials and is equal to the absorbed wave divided by the incident wave. The third, and most important for auditorium purposes, effect on sound waves is reverberation. Reverberation is caused by the collection of reflected waves in an enclosure, and is used to overcome the inverse square law problem that acoustical engineers are faced with. Too much reverberation, however, can cause sound waves to sound muddy and unarticulated, which is never good for an auditorium setting. To perfect the level of reverberation, a quantity of reverberation time is used. Over time, the sound waves reflecting off of surfaces will steadily decrease because of the previously-discussed property of absorption, thus the intensity of the sound will slowly diminish. The reverberation time is calculated by the time it takes for a sound s intensity to decrease by 60deciebels, or 60dB, below its original intensity. The formula for a reverberation time is R =.161V/S, where R is reverberation time, V is the volume of the room in meters 3, and S is the total effective absorbing area of all walls, or the absorption constant multiplied by the area of each wall. So what structures to acoustical engineers work with, and how do they calculate what a room should look like? Well there are plenty of different types of rooms they create, each with its own purpose, and thus its own levels of absorption and reflection to create a perfect reverberation. These rooms include auditoriums and lecture halls, anechoic chambers, whispering galleries, and reverberation rooms.

5 Killam 5 When an acoustical engineer works on the design for an auditorium or a lecture, there are a lot of things they must take in to account. Firstly, they need effective projection of the sound all the way to the rear end of the room. In other words, they must overcome the inverse square law. That is conquered using a high ceiling of a reflective material and a specifically long reverberation time. In general-use auditoriums, where music needs a bit of reverberation and resonance through the halls, the prime reverberation time is seconds. In auditoriums for music-only use, the wanted reverberation time is greater, while in auditoriums for speaking purposes, such as lecture halls, the desired reverberation time is lower. Another thing acoustical engineers must worry about is blocking the direct path of sound. Clarity of sound can be diminished by anything in the way of the direct sound wave from the source to the listener. Even dispersion of a sound is also very important, else there may be prominent, unwanted echoes, or reverberation dead spots, meaning very low reverberation time. The way to create an even dispersion of sound is to avoid large, flat surfaces for sound to reflect off of. Instead, acoustical engineers create halls that have angled, broken segments of wall on either side, and have the walls slowly get closer as you go more towards the rear of the auditorium, as opposed to laying them parallel. The first building that was created with the use of acoustics in mind was the Symphony Hall in Boston, Massachusetts. Created in 1900, it was designated a US National Historic Landmark in 1999 and is still today among the top three concert halls in the world for its acoustics. The designer, Clement Sabine, was an assistant professor of physics at Harvard University, who ended up creating the formula for reverberation time, which is known at the Sabine Formula, or, as previously mentioned, R =.161V/S.

6 Killam 6 Anechoic chambers are exactly what they sound like: rooms that are created for the purpose of minimizing echoes, thus reflection, as much as possible. They focus on creating surfaces that will complete absorb any sound wave hitting them, creating a perfect, soundless room for many different sorts of tests that would be otherwise disturbed by the noises of the normal world. There are two ways of making an anechoic chamber: tiles, and pyramidal. The former consists of flat plates of ferrite fixed to all interior surfaces of the room. It is the more durable of the two, but is less effective at higher frequencies. The second way of making an anechoic chamber, pyramidal, consists of rubbery foam in the shape of pyramids jutting out of the wall from all areas. The length of these pyramids depends on the frequency desired for testing. The length of the pyramids is roughly one-fourth of the wavelength, which is equal to the velocity of the wave divided by its frequency. Pyramids in an anechoic chamber vary from 2 inches to 24 inches in length. TILES PYRAMIDAL A whispering gallery is an interesting piece of acoustic architecture. It is usually a circular or elliptical area enclosed beneath a dome. The interesting portion of this is that if one stands at a certain area of the gallery and whispers, someone in a completely different part of the room can hear the whisper like it originated right next to them. This is because the sound is carried by a specific type of wave called a whispering-gallery wave, which travel around concave surfaces. The sound from one end of the chamber travels around the circumference of the circle to the point directly opposite from it, so that nobody except a person standing in the second spot can hear what the person whispered. These waves were originally discovered in the

7 Killam 7 whispering gallery of St Paul s Cathedral by Lord Rayleigh, an English physicist who discovered argon. Opposite of anechoic chambers, reverberation rooms are designed for the purpose of complete reflection and zero absorption. To create this effect, reverberation rooms are large chambers with very hard exposed surfaces. These surfaces are also all non-parallel to help to create standing waves, which are waves that remain in a constant position, thus not diminishing over time. Much like the anechoic chambers, these rooms are used for experiments, but different experiments than the anechoic chambers. A specific type of reverberation room used for music recording is called an echo chamber. Through my research, I have discovered the purpose of acoustics in architecture, and I ve learned why each part of an auditorium is created just like it is, for each part is where it is for a specific reason. I also learned much more about absorption, reflection, and reverberation, and all of the mathematic properties behind each one of them. I now know much more about both architecture and acoustics, and the physics and mathematics behind both of them. Works Cited Backus, John. The Acoustical Foundations of Music. New York: Norton, Print. Reverberation N.p, n.d. Web. 4 Dec What is Acoustics? N.p, n.d Web. 29 Nov 2013 < The Quietest Room In The World N.p, Patricia Kelly 1 Nov 2013 < September-2008>

Lab #6 Room Acoustics

EQUIPMENT Physics of Music PHY103 Lab Manual Lab #6 Room Acoustics Tape measures Noise making devices (pieces of wood for clappers). Microphones, stands, preamps connected to computers. Extra XLR microphone

8 Room and Auditorium Acoustics

8 Room and Auditorium Acoustics Acoustical properties of rooms and concert halls are mainly determined by the echo that depends on the reflection and absorption of sound by the walls. Diffraction of sound

LAB 9 Waves and Resonance

Cabrillo College Physics l0l Name LAB 9 Waves and Resonance Read Hewitt Chapter 19 What to learn and explore Almost all of the information that we receive from our environment comes to us in the form of

Waves Review Checklist Pulses 5.1.1A Explain the relationship between the period of a pendulum and the factors involved in building one

5.1.1 Oscillating Systems Waves Review Checklist 5.1.2 Pulses 5.1.1A Explain the relationship between the period of a pendulum and the factors involved in building one Four pendulums are built as shown

How does Architecture Affect the Acoustics of a Space

How does Architecture Affect the Acoustics of a Space Grade Level This lesson plan was developed for a 9 th grade Physical Science Class. Objectives To develop aural senses of spatial awareness To understand

Waves are created by disturbances which cause vibrations.

Wave Motion Waves are created by disturbances which cause vibrations. Vibrations produce a back-and-forth type motion called an oscillation. http://3d wave simulation The number of vibrations (or waves)

Lesson 26: Reflection & Mirror Diagrams

Lesson 26: Reflection & Mirror Diagrams The Law of Reflection There is nothing really mysterious about reflection, but some people try to make it more difficult than it really is. All EMR will reflect

Acoustic design according to room shape

Acoustic design according to room shape The shape of the room defines the movement of the sound waves within the room. Placement of acoustic materials should be determined by the way the sound moves in

Physical Science Study Guide Unit 7 Wave properties and behaviors, electromagnetic spectrum, Doppler Effect

Objectives: PS-7.1 Physical Science Study Guide Unit 7 Wave properties and behaviors, electromagnetic spectrum, Doppler Effect Illustrate ways that the energy of waves is transferred by interaction with

Waves Sound and Light

Waves Sound and Light r2 c:\files\courses\1710\spr12\wavetrans.doc Ron Robertson The Nature of Waves Waves are a type of energy transmission that results from a periodic disturbance (vibration). They are

Acoustical Design for Concert Hall in the Science and Art Centre of Xiamen University

Acoustical Design for Concert Hall in the Science and Art Centre of Xiamen University Yuezhe Zhao, Shuoxian Wu State Key Laboratory of Subtropical Building Sciences, South China University of Technology,

ROOM ACOUSTICS DESIGN. Room Acoustics Design Intent: Appropriate Articulation

ROOM ACOUSTICS DESIGN http://mikebm.files.wordpress.com/2008/06/walt-disney-hall-1.jpg Ball State Architecture ENVIRONMENTAL SYSTEMS 1 Grondzik 1 Room Acoustics Design Intent: Appropriate Articulation

Relationship between Sound Pressure and Sound Power Levels

Relationship between Sound Pressure and Sound Power Levels 4 W. T. W. CORY Chairman of the Eurovent WG 1 Fans If we wish to know the sound power transmitted through a fan and ducting system, it is preferable

8. ACOUSTICS OF ROOMS AND ENCLOSURES

NOISE CONTROL Room Acoustics 8.1 8. ACOUSTICS OF ROOMS AND ENCLOSURES 8.1 Introduction This section covers the acoustics of enclosed spaces. Upon completion, the reader should have a basic understanding

Lab Question 1. Faster because the particles are moving faster which means the compressions and rarefactions move faster

Lab Results Lab Question 1 Faster because the particles are moving faster which means the compressions and rarefactions move faster Lab Question 2 Velocity = 2 x / t 343 = 2 (7.8) / t t = 15.6 / 343 =

CEPro. Advantage Series. Diagrammatic Guide to In-Ceiling Speaker Placement for Home Theater, Multiroom Audio

CEPro Advantage Series Diagrammatic Guide to In-Ceiling Speaker Placement for Home Theater, Multiroom Audio Diagrammic Guide to In-Ceiling Speaker Placement for Home Theater Multiroom Audio 2013 EH Publishing

Acoustic design according to room type

according to room type The purpose of the room is decisive for the acoustic environment to be created. In rooms for speech, such as classrooms and auditoriums, it is important to ensure a good level of

Waves. Transverse Waves

Waves A wave is a repeated oscillation or disturbance that transfers energy through matter or space. The two primary types of waves are Transverse Longitudinal Transverse Waves In a transverse wave, the

PS-7.2 Compare the nature and properties of transverse and longitudinal/compressional mechanical waves.

PS-7.1 Illustrate ways that the energy of waves is transferred by interaction with matter (including transverse and longitudinal /compressional waves). Understand that a wave is a repeating disturbance

Look at the picture below. With the person next to you, discuss what this might be.

WAVES Unit 10 Look at the picture below. With the person next to you, discuss what this might be. SECTION 1: THE NATURE OF WAVES A. Wave a repeating disturbance or movement that transfers energy through

Waves. Wave: A traveling disturbance consisting of coordinated vibrations that transmit energy with no net movement of the matter.

Waves Wave: A traveling disturbance consisting of coordinated vibrations that transmit energy with no net movement of the matter. Source: some kind of disturbance from the state of equilibrium. Propagation:

Acoustic Terms, Definitions and General Information

Acoustic Terms, Definitions and General Information Authored by: Daniel Ziobroski Acoustic Engineer Environmental and Acoustic Engineering GE Energy Charles Powers Program Manager Environmental and Acoustic

Acoustical requirements of Dewan Filharmonik Petronas, Malaysia

Acoustical requirements of Dewan Filharmonik Petronas, Malaysia Husrul Nizam Husin, Syed Abdul Haris bin Syed Mustapa and Kamarul Syahril Kamal Universiti Teknologi MARA, Cawangan Perak, Malaysia ABSTRACT

NOTES Unit 13: Waves and Optics Wave Motion and Sound

Unit 13: Waves and Optics Wave Motion and Sound OBJECTIVES: Big Idea 6: Waves can transfer energy and momentum from one location to another without the permanent transfer of mass and serve as a mathematical

Waves Review Checklist Pulses 5.1.1A Explain the relationship between the period of a pendulum and the factors involved in building one

5.1.1 Oscillating Systems Waves Review hecklist 5.1.2 Pulses 5.1.1A Explain the relationship between the period of a pendulum and the factors involved in building one Four pendulums are built as shown

Ch 26 Chapter Review Q & A s

Ch 26 Chapter Review Q & A s Q: What is the source of all sounds? A: vibrating objects Q: How does pitch relate to frequency? A: Pitch is subjective, but it increases as frequency increases Q: What is

Standing Waves and the Velocity of Sound

Chapter 8 Standing Waves and the Velocity of Sound 8.1 Purpose In this experiment we will be using resonance points of a sound wave traveling through an open tube to measure the speed of sound in air.

Sound Power Measurement

Sound Power Measurement A sound source will radiate different sound powers in different environments, especially at low frequencies when the wavelength is comparable to the size of the room 1. Fortunately

Building Technology and Architectural Design. Program 4th lecture 9.00-9.45 Case studies Room Acoustics. 10.00 10.45 Case studies Room Acoustics

Building Technology and Architectural Design Program 4th lecture 9.00-9.45 Case studies Room Acoustics 9.45 10.00 Break 10.00 10.45 Case studies Room Acoustics Lecturer Poul Henning Kirkegaard 10-10-2006

Chapter 5 Perspective in Motion: Galilean Relativity and the Doppler Effect

Chapter 5 Perspective in Motion: Galilean Relativity and the Doppler Effect Much can be and has been written about the astronomer, mathematician, and physicist Galileo Galilei (1564-1642). Galileo's was

How can Lightspeed s sound panel solutions possibly break down acoustic barriers in the classroom?

How can Lightspeed s sound panel solutions possibly break down acoustic barriers in the classroom? There is no audio solution that throws sound. There is no solution that overcomes the laws of physics.

1/28/2009. Motion that repeats itself over and over. Rotation and revolution of Earth Back and forth motion of a swing Turning bicycle wheel

Physics: Waves and Sound Dr. Ed Brothers Chemistry and Physics for High School Students Texas A&M (Qatar) January 27, 2009 Harmonic Motion Motion that repeats itself over and over Examples of harmonic

2011-06-13. Acoustic design with wall acoustic solutions

2011-06-13 Acoustic design with wall acoustic solutions Introduction A suspended ceiling is by far the most common acoustical treatment in a room. In most cases this is also a sufficient solution to create

PSS 27.2 The Electric Field of a Continuous Distribution of Charge

Chapter 27 Solutions PSS 27.2 The Electric Field of a Continuous Distribution of Charge Description: Knight Problem-Solving Strategy 27.2 The Electric Field of a Continuous Distribution of Charge is illustrated.

Psychology of Language

PSYCH 155/LING 155 UCI COGNITIVE SCIENCES syn lab Psychology of Language Prof. Jon Sprouse Lecture 3: Sound and Speech Sounds 1 The representations and processes of starting representation Language sensory

IT S TIME TO RETHINK THE ACOUSTICS OF MOVIE THEATRES

IT S TIME TO RETHINK THE ACOUSTICS OF MOVIE THEATRES BY JOHN F. ALLEN What defines good acoustics? Who invented the concept? Are the acoustics of modern motion picture theatres as good as they could be?

General Physics (PHY 2130)

General Physics (PHY 2130) Lecture 28 Waves standing waves Sound definitions standing sound waves and instruments Doppler s effect http://www.physics.wayne.edu/~apetrov/phy2130/ Lightning Review Last lecture:

Canalis. CANALIS Principles and Techniques of Speaker Placement

Canalis CANALIS Principles and Techniques of Speaker Placement After assembling a high-quality music system, the room becomes the limiting factor in sonic performance. There are many articles and theories

Optiffuser. High-performance, high bandwidth lightweight 1D diffuser.

Optiffuser High-performance, high bandwidth lightweight 1D diffuser. General product information The Optiffuser comes in packs of four panels. Two positives and two negatives (see page 5) per package.

Lecture 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

Waves - Transverse and Longitudinal Waves

Waves - Transverse and Longitudinal Waves wave may be defined as a periodic disturbance in a medium that carries energy from one point to another. ll waves require a source and a medium of propagation.

Periodic Wave Phenomena

Name: Periodic Wave Phenomena 1. The diagram shows radar waves being emitted from a stationary police car and reflected by a moving car back to the police car. The difference in apparent frequency between

Name Class Date. A wave is produced that moves out from the center in an expanding circle. The wave

Exercises 25.1 Vibration of a Pendulum (page 491) 1. The time it takes for one back-and-forth motion of a pendulum is called the period. 2. List the two things that determine the period of a pendulum.

Acoustical Design of Rooms for Speech

Construction Technology Update No. 51 Acoustical Design of Rooms for Speech by J.S. Bradley This Update explains the acoustical requirements conducive to relaxed and accurate speech communication in rooms

Waves and Sound Part 1

Waves and Sound Part 1 Intro Write the following questions on a blank piece of paper (don t answer yet) 1. What is the difference between a mechanical and electromagnetic wave? 2. What is the difference

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

Exam Name MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) A 660-Hz tone has an intensity level of 54 db. The velocity of sound in air is 345 m/s.

Michael Svec Students will understand how images are formed in a flat mirror.

Unit Title Topic Name and email address of person submitting the unit Aims of unit Indicative content Resources needed Teacher notes Forming Images Physics Light and optics Michael Svec Michael.Svec@furman.edu

Nicholas J. Giordano. Chapter 12 Waves

Nicholas J. Giordano www.cengage.com/physics/giordano Chapter 12 Waves Wave Motion A wave is a moving disturbance that transports energy from one place to another without transporting matter Questions

2) In terms of wave motion, define medium. The type of matter a wave moves through is the medium.

Waves Classwork #1 What is a wave? 1) What causes a wave? A disturbance that travels through space or matter. 2) In terms of wave motion, define medium. The type of matter a wave moves through is the medium.

Junior Math Circles March 10, D Geometry II

1 University of Waterloo Faculty of Mathematics Junior Math Circles March 10, 2010 3D Geometry II Centre for Education in Mathematics and Computing Opening Problem Three tennis ball are packed in a cylinder.

Sample Questions for the AP Physics 1 Exam

Sample Questions for the AP Physics 1 Exam Sample Questions for the AP Physics 1 Exam Multiple-choice Questions Note: To simplify calculations, you may use g 5 10 m/s 2 in all problems. Directions: Each

JdB Sound Acoustics Presents

JdB Sound Acoustics Presents KINGSTON ROAD UNITED CHURCH S A N C T U A RY A C O U S T I C S A N D S O U N D S Y S T E M B Y J O S E P H D E B U G L I O 2 0 0 8 Copyright by Joseph De Buglio 2008 The Beginning

Improving acoustics. For better learning environments

Improving acoustics For better learning environments The natural environment The model for learning spaces Over thousands of years, the human sense of hearing evolved for an outdoor, natural environment.

v = λ f this is the Golden Rule for waves transverse & longitudinal waves Harmonic waves The golden rule for waves Example: wave on a string Review

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

transverse wave on a string Slinky waves

L 23 Vibrations and Waves [3] updated 10/23/07 resonance clocks pendulum springs harmonic motion mechanical waves sound waves golden rule for waves musical instruments The Doppler effect Doppler radar

The Acoustics of Indoor Aquatic Facilities: How Improving Sound Levels Impacts Both our Physiological and Psychological Well Being Jeffrey Madison

The Acoustics of Indoor Aquatic Facilities: How Improving Sound Levels Impacts Both our Physiological and Psychological Well Being Jeffrey Madison A lifelong musician, Jeff began his career in 1992 when

Audio Analysis & Creating Reverberation Plug-ins In Digital Audio Engineering

, pp.201-208 http:// dx.doi.org/10.14257/ijmue.2013.8.6.20 Audio Analysis & Creating Reverberation Plug-ins In Digital Audio Engineering Yoemun Yun Dept. of Applied Music, Chungwoon University Daehakgil-25,

HUDSONVILLE HIGH SCHOOL COURSE FRAMEWORK

HUDSONVILLE HIGH SCHOOL COURSE FRAMEWORK COURSE / SUBJECT Physics Concepts Unit 1: Chapter 2 - Mechanical Equilibrium Chapter 3 - Newton s 1st Law Chapter 4 - Linear Motion Pacing: 3 Weeks Lessons/Activities:

Geometry and Measurement

The student will be able to: Geometry and Measurement 1. Demonstrate an understanding of the principles of geometry and measurement and operations using measurements Use the US system of measurement for

Lecture 6. Weight. Tension. Normal Force. Static Friction. Cutnell+Johnson: 4.8-4.12, second half of section 4.7

Lecture 6 Weight Tension Normal Force Static Friction Cutnell+Johnson: 4.8-4.12, second half of section 4.7 In this lecture, I m going to discuss four different kinds of forces: weight, tension, the normal

Q1. The diagram shows a plane mirror used by a dentist to see the back of a patient s tooth.

Year 0 Physics Waves Revision questions Higher Name: Q. The diagram shows a plane mirror used by a dentist to see the back of a patient s tooth. (a) Use a ruler to draw a ray of light on the diagram to

Chapter 23 Multiple Choice Test

Name: Class: Date: Chapter 23 Multiple Choice Test Multiple Choice Identify the choice that best completes the statement or answers the question. 1. A unit of motion repeated over and over again is called

Data Communications Prof. Ajit Pal Department of Computer Science & Engineering Indian Institute of Technology, Kharagpur Lecture # 03 Data and Signal

(Refer Slide Time: 00:01:23) Data Communications Prof. Ajit Pal Department of Computer Science & Engineering Indian Institute of Technology, Kharagpur Lecture # 03 Data and Signal Hello viewers welcome

Technical Notes 5A - Sound Insulation - Clay Masonry Walls (Reissued August 2000) INTRODUCTION

Technical Notes 5A - Sound Insulation - Clay Masonry Walls (Reissued August 2000) INTRODUCTION The sound insulation or sound transmission loss of a wall is that property which enables it to resist the

Microwave Antennas and Radar. Maria Leonora Guico Tcom 126 2 nd Sem Lecture 8

Microwave Antennas and Radar Maria Leonora Guico Tcom 126 2 nd Sem Lecture 8 G P P directional isotropic Antenna Basics Isotropic Dipole High gain directional 0 db i 2.2 db i 14 db i Antenna performance

A: zero everywhere. B: positive everywhere. C: negative everywhere. D: depends on position.

A string is clamped at both ends and then plucked so that it vibrates in a standing wave between two extreme positions a and c. (Let upward motion correspond to positive velocities.) When the

CHAPTER 8, GEOMETRY. 4. A circular cylinder has a circumference of 33 in. Use 22 as the approximate value of π and find the radius of this cylinder.

TEST A CHAPTER 8, GEOMETRY 1. A rectangular plot of ground is to be enclosed with 180 yd of fencing. If the plot is twice as long as it is wide, what are its dimensions? 2. A 4 cm by 6 cm rectangle has

Spectroscopy in Astronomy: Emission Spectra

Spectroscopy in Astronomy: Emission Spectra Equipment: (Shared among all lab groups) Blue spectrometer (one for each lab group) Spectrum tube power supplies (5000 volts be careful!) These will be set up

Wave Energy. A pulse is a traveling disturbance in a medium. Pictures (a) through (d) show successive positions of a pulse in a rope.

Wave Energy A pulse is a traveling disturbance in a medium. Pictures (a) through (d) show successive positions of a pulse in a rope. Wave Energy A wave is a succession of pulses, traveling through a medium.

The Reflexion Filter. Manual. Electronics

The Reflexion Filter Manual Electronics SE Electronics Instrument Reflexion Filter Manual Thank you for purchasing the Reflexion Filter portable vocal booth. The main idea behind this product is to facilitate

2.1. Inductive Reasoning EXAMPLE A

CONDENSED LESSON 2.1 Inductive Reasoning In this lesson you will Learn how inductive reasoning is used in science and mathematics Use inductive reasoning to make conjectures about sequences of numbers

Waves review practice questions

Name: ate: 1. The diagram shown represents four waves traveling to the right in the same transmitting medium. 4. Which wave has the greatest amplitude?.... Which type of wave is represented? 5. Which characteristic

(text on screen) VO In diffuse reflection, parallel incident light rays are reflected in different directions.

Physics 1401 Mirrors You ve probably heard the old saying, The end is in sight. Well, that saying applies doubly to our class. Not only do we start the final unit that ends our year of physics but today

S15--AP Phys Q3 SHO-Sound PRACTICE

Name: Class: Date: ID: A S5--AP Phys Q3 SHO-Sound PRACTICE Multiple Choice Identify the choice that best completes the statement or answers the question.. If you are on a train, how will the pitch of the

I n spite of many attempts to surpass

WHAT IS SO SPECIAL ABOUT SHOEBOX HALLS? ENVELOPMENT, ENVELOPMENT, ENVELOPMENT Marshall Long Marshall Long Acoustics 13636 Riverside Drive Sherman Oaks, California 91423 I n spite of many attempts to surpass

Area of Parallelograms (pages 546 549)

A Area of Parallelograms (pages 546 549) A parallelogram is a quadrilateral with two pairs of parallel sides. The base is any one of the sides and the height is the shortest distance (the length of a perpendicular

Activity Description: Students correctly complete the Everyday Examples of Thermodynamics matching pieces and the Student Worksheet.

Activity Description: Students correctly complete the Everyday Examples of Thermodynamics matching pieces and the Student Worksheet. Materials: 1 Student Attachment: Student Worksheet (per student) 1 Student

Acoustical Design of a Multi-Purpose Hall for Natural and Amplified Sound

Acoustical Design of a Multi-Purpose Hall for Natural and Amplified Sound Dirun Ergin Talayman Acoustics Ltd, Istanbul, Turkey. Zerhan Yüksel Can Yıldız Technical University, Istanbul, Turkey. Summary

ACOUSTIC PERFORMANCES OF AN HEMIANECHOIC ROOM FOR ELECTROMAGNETIC COMPATIBILITY TESTS

ACOUSTIC PERFORMANCES OF AN HEMIANECHOIC ROOM FOR ELECTROMAGNETIC COMPATIBILITY TESTS Franco Cotana, Federico Rossi, Andrea Nicolini Università degli Studi di Perugia, Dipartimento di Ingegneria Industriale

wavelength λ Amplitude of the wave A λ crest A trough observer speed of the wave v Period of the wave P λ = v P frequency f, f = 1/P v =λ f

Waves Traveling waves: Traveling, periodic, sinusoidal (Shaped like a mathematical sine wave) water waves, sound waves, electromagnetic waves, and others, share certain features shown in the figure. The

Guidelines for video conferencing room acoustics. D14377.01 September 2010

Guidelines for video conferencing room acoustics D14377.01 September 2010 Video conferencing room acoustics Does the audio quality fail to meet your expectations? Do you feel tired when spending longer

Improving the Acoustics in a Historic Building Using Axiomatic Design and TRIZ

Improving the Acoustics in a Historic Building Using Axiomatic Design and TRIZ Andrew Kankey atk127@psu.edu Department of Acoustics Pennsylvania State University University Park, PA 16801 Abstract Madara

Microwave Measurements with Network Analyzer Design of RFID Antenna. In the Course Circuit Theory By: Johan Sidén

Microwave Measurements with Network Analyzer Design of RFID Antenna In the Course Circuit Theory By: By: 1(9) In this laboratory work you will show your classmates that you can get the best resonance on

Wave Interference and Resonance

Wave Interference and Resonance 1. An audio frequency oscillator produces a single frequency sound wave but sends it through two speakers 1 m apart from each other. An observer standing 10.0 m away from

PHYSICS 202 Practice Exam Waves, Sound, Reflection and Refraction. Name. Constants and Conversion Factors

PHYSICS 202 Practice Exam Waves, Sound, Reflection and Refraction Name Constants and Conversion Factors Speed of sound in Air œ \$%!7Î= "'!*7/>/

Absorption Coefficients and Impedance Daniel A. Russell Science and Mathematics Department, Kettering University, Flint, MI, 48504

Absorption Coefficients and Impedance Daniel A. Russell Science and Mathematics Department, Kettering University, Flint, MI, 48504 1 I. Introduction and ackground In this laboratory exercise you will measure

Doppler Effect Plug-in in Music Production and Engineering

, pp.287-292 http://dx.doi.org/10.14257/ijmue.2014.9.8.26 Doppler Effect Plug-in in Music Production and Engineering Yoemun Yun Department of Applied Music, Chungwoon University San 29, Namjang-ri, Hongseong,

Sound Waves. PHYS102 Previous Exam Problems CHAPTER. Sound waves Interference of sound waves Intensity & level Resonance in tubes Doppler effect

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,

Experiment 1: SOUND. The equation used to describe a simple sinusoidal function that propagates in space is given by Y = A o sin(k(x v t))

Experiment 1: SOUND Introduction Sound is classified under the topic of mechanical waves. A mechanical wave is a term which refers to a displacement of elements in a medium from their equilibrium state,

Acoustics and Sound Systems in Architectural Design

Acoustics and Sound Systems in Architectural Design By RICK KAMLET The need for intelligible speech or pleasant, undistorted music is fundamental to the design of auditoriums, performing arts centers,

W AVES. Chapter 6 OUTLINE GOALS. 6.9 Types of EM Waves 6.10 Light Rays

Chapter 6 W AVES OUTLINE Wave Motion 6.1 Water Waves 6.2 Transverse and Longitudinal Waves 6.3 Describing Waves 6.4 Standing Waves Sound Waves 6.5 Sound 6.6 Doppler Effect 6.7 Musical Sounds Electromagnetic

THE ALGORITHMIC AUDITORIUM. A computational model for auditorium design. 1. Introduction

THE ALGORITHMIC AUDITORIUM A computational model for auditorium design GANAPATHY MAHALINGAM Department of Architecture and Landscape Architecture North Dakota State University Fargo, North Dakota USA Abstract.

Sound and stringed instruments

Sound and stringed instruments Lecture 14: Sound and strings Reminders/Updates: HW 6 due Monday, 10pm. Exam 2, a week today! 1 Sound so far: Sound is a pressure or density fluctuation carried (usually)

VIRTUAL SPACE 4D PROJECT: THE ROOM ACOUSTICAL TOOL. J. Keränen, P. Larm, V. Hongisto

VIRTUAL SPACE 4D PROJECT: THE ROOM ACOUSTICAL TOOL David Oliva University of Turku Department of Physics FIN-20014 Turku, Finland. david.elorza@ttl.fi J. Keränen, P. Larm, V. Hongisto Finnish Institute

Chapter 21 Mechanical Waves. A PowerPoint Presentation by Paul E. Tippens, Professor of Physics Southern Polytechnic State University

Chapter 21 Mechanical Waves A PowerPoint Presentation by Paul E. Tippens, Professor of Physics Southern Polytechnic State University 2007 Objectives: After completion of this module, you should be able

Areas of Rectangles and Parallelograms

CONDENSED LESSON 8.1 Areas of Rectangles and Parallelograms In this lesson you will Review the formula for the area of a rectangle Use the area formula for rectangles to find areas of other shapes Discover

Basic Concepts of Sound. Contents: Definitions db Conversion Sound Fields db ± db

Basic Concepts of Sound Contents: Definitions db Conversion Sound Fields db ± db BA 7666-11, 1 Abstract This lecture introduces sound and sound measurements by describing sound pressure, sound level and

THE ACOUSTICS OF THE "NUOVO TEATRO COMUNALE" IN CAGLIARI

Roberto Pompoli(1), Angelo Farina(2), Patrizio Fausti(1) (1) Istituto di Ingegneria, University of Ferrara, Italy (2) Dipartimento di Ingegneria Industriale, University of Parma, Italy 1. ABSTRACT In 1967,