Sound Intensity and Resonance

Slides:



Advertisements
Similar presentations
Chapter 14 Sound.
Advertisements

Sound. Sound Waves  Sound waves are longitudinal waves.  The source of a sound wave is a vibrating object.  Only certain wavelengths of longitudinal.
All sounds are produced by the vibration of matter. If there is no vibration, there is no sound.
Chapter 13 Section 1 Sound Waves. Sound Waves What are they? – Longitudinal – Require medium.
Sound Chapter 13.
Lesson 3 - Logs and Levels Math Prereqs. Examples Without using your calculator, find the following: (log 10 (2) = 0.30) log 10 (10 -3 ) = log 10 (1 x.
+ Perceiving Sound. + Before we start! A review of Light.
Sound. If a tree falls in the forest and there is nobody around does it make a sound?
What is sound? Sound is a longitudinal wave produced by a vibrating source Examples of sources: tuning fork, vocal cords, lips or reed on a musical instrument.
Chapter 12 Preview Objectives The Production of Sound Waves
Chapter 12: Sound A few (selected) topics on sound
Sound Waves. Review Do you remember anything about _______? Transverse waves Longitudinal waves Mechanical waves Electromagnetic waves.
SOUND WAVES PRODUCTION  Vibrating prongs set the air molecules in motion  Top: molecules closer together high air pressure (compression)  Bottom:
Sound Waves Three things to know about sound waves: 1)There must be a source for a sound wave, that source will be a vibrating object. 2)The energy transferred.
Holt Physics Chapter 12 Sound.
SOUND Longitudinal Wave Travels through some medium Cannot travel through a vacuum How does vibrating drum produce sound? Skin moving up presses air.
Ch. 13, section 2 – pages A. Intensity - rate of energy flow through an area energy is transferred from one air molecule to the next as the wave.
Week 2 Sound Physics, Ranges of Hearing Frequency, Wavelength, Period, Velocity Audio Engineering & Sound Production Unit code: AUD202 AUDIO & ACOUSTICS.
Sound Physics. Sound Source All sounds are produced by the vibrations of material objects The frequency of sounds is often described by the word pitch.
Physics of Sound WAVES. Sound is a wave. It is a wave of energy that moves through matter; solids, liquids, gases.
© Houghton Mifflin Harcourt Publishing Company Preview Objectives The Production of Sound Waves Frequency of Sound Waves The Doppler Effect Chapter 12.
Sources of Sound  sound is a mechanical wave produced by vibrations that occur in a medium-- generally air  sound is a longitudinal wave.
The production of sound Waves always begin with A vibrating object.
Sound Waves Can you hear me now?. Wave Review Sound is a Longitudinal Wave- it moves back and forth like a spring. Sound is a Mechanical Wave- it needs.
Properties of Sound. Pitch Loudness Speed in Various Media.
Intensity of a Spherical Wave
Chapter 26: Sound. The Origin of Sound  All sounds are produced by the vibrations of material objects  Pitch – our subjective impression of sound 
Waves Mechanical Electromagnetic Medium Transfer of … Pulse Periodic Perpendicular Parallel.
SPH3U: Waves & Sound Wave Speed & Sound. The Universal Wave Equation Recall that the frequency of a wave is the number of complete cycles that pass a.
Sound Intensity and Intensity Level
13-2: Sound Intensity and Resonance Objectives: Calculate the intensity of sound waves. Relate intensity, decibel level, and perceived loudness. Explain.
Honors Physics Chapter 14
Sound Waves The production of sound from a sound wave begins with a vibrating object.
Chapter 12 Preview Objectives The Production of Sound Waves
Sound and Hearing. Basic Facts Longitudinal wave Audible range (human): 20Hz – 20,000Hz.
Chapter 12 Sound. The Origin of Sound  Sound is a longitudinal, mechanical wave.  You can hear sound with a frequency of 20 – 20,000 Hz. Under 20 hz.
Wave Motion Types of mechanical waves  Mechanical waves are disturbances that travel through some material or substance called medium for the waves. travel.
Physics Section 12.2 Apply the sound properties of intensity and resonance Intensity is the rate at which energy flows through a unit area perpendicular.
Sound. Review Sound is a mechanical wave Sound is a mechanical wave
Alternately compresses and then rarefies (spreads out) the air molecules Created by vibrating matter ex. Tuning fork Sound is a longitudinal wave; air.
Sound. Sound Intensity Intensity – the rate of energy flow through a given area.
Physics Mrs. Dimler SOUND.  Every sound wave begins with a vibrating object, such as the vibrating prong of a tuning fork. Tuning fork and air molecules.
Holt Physics Chapter 13 Sound.
SOUND.
Sound.
Unit 2 Lesson 1 Sound Waves and Hearing
CHAPTER 13 Sound.
Unit 2 Lesson 1 Sound Waves and Hearing
Physics 7E Prof. D. Casper.
SOUND A NOISY SUBJECT.
Ch Sound The Nature of Sound Speed of Sound Human Hearing
Sound Intensity & Resonance
Higher Intensity (Volume)
Ch Waves & Sound II. The Nature of Sound Speed of Sound
Sound and Intensity Transverse vs. Longitudinal Waves Sound Frequency
Ch Waves & Sound II. The Nature of Sound Speed of Sound
Reflection Superposition Interference
Ch Waves & Sound II. The Nature of Sound Speed of Sound
Ch Waves & Sound II. The Nature of Sound Speed of Sound
Sound.
Sound.
All sounds are produced by the vibration of matter
Sound Intensity and Resonance
Ch Waves & Sound II. The Nature of Sound Speed of Sound
Ch Waves & Sound II. The Nature of Sound Speed of Sound
Sound Waves, Pitch, and Loudness
Waves & Sound The Nature of Sound Speed of Sound Human hearing
Sound 13.2.
Sound.
Presentation transcript:

Sound Intensity and Resonance

What is Sound Intensity?

Textbook Definition: Sound waves traveling in air are longitudinal waves. As the sound waves travel outward from the source, energy is transferred from one air molecule to the next. The rate at which this energy is transferred through a unit area of the plane wave is called the intensity of the wave.

Example 1 What is the intensity of the sound waves produced by a trumpet at a distance of 3.2 m when the power output of the trumpet is 0.20 W? Assume that the sound waves are spherical.

Range of Human Hearing Human hearing depends on both the frequency and the intensity of sound waves. Sounds in the middle of the spectrum of frequencies can be heard more easily (at lower intensities) than those at lower and higher frequencies. The human threshold of hearing is at 1000 Hz and 1.0x10-12 W/m2. The threshold of pain is 1.0 W/m2.

Decibels (dB) – Relative Intensity Relative Intensity is the ratio of the intensity of a given sound wave to the intensity at the threshold of hearing. The decibel scale is logarithmic (base 10). Random Fact: The original unit of decibel level is the bel, named in honor of Alexander Graham Bell, the inventor of the telephone. The decibel is equivalent to 0.1 bel

On the decibel scale, the smallest audible sound (near total silence) is 0 dB. A sound 10 times more powerful is 10 dB. A sound 100 times more powerful than near total silence is 20 dB. A sound 1,000 times more powerful than near total silence is 30 dB. Physics Class Most Days

Intensity Level (Decibel Level) 𝛽=10 log 𝐼 𝐼 𝑜 Where: I is the intensity of the sound, Io is the threshold of hearing (1.0x10-12 W/m2) B = the intensity level in decibels

Practice Problem An 80 W guitar amplifier is played at maximum volume. If you are standing 12.0 m from the amplifier, how many decibels of sound are you hearing?

Resonance (Forced Vibrations) Textbook Definition: a phenomenon that occurs when the frequency of a force applied to a system matches the natural frequency of vibration of the system, resulting in a large amplitude of vibration Resonance Explained Resonance Demo