chapter 11 types of waves - manasquan public schools
TRANSCRIPT
Chapter 11 Types of WavesSection 11.1Section 11.1
WavesWaves A disturbance that A disturbance that transmits energy through transmits energy through matter or spacematter or space
WavesWaves Most waves move Most waves move through through mattermatter called a called a mediummedium.. Ex. Waves traveling Ex. Waves traveling through water. through water.
Types of WavesTypes of Waves 1. Mechanical Waves1. Mechanical Waves a wave that requires a a wave that requires a medium through which to medium through which to traveltravel Most type of wavesMost type of waves
Ex.Ex. Sound, seismicSound, seismic
Types of WavesTypes of Waves 2. Electromagnetic Waves2. Electromagnetic Waves waves caused by the waves caused by the disturbance in electric and disturbance in electric and magnetic fields and that magnetic fields and that does does not require a mediumnot require a medium..
(light radiation waves)(light radiation waves)
What do Waves Do?What do Waves Do? When waves travel When waves travel through media they are through media they are doing work (energy doing work (energy transferred). transferred). Ex. Sound traveling in your Ex. Sound traveling in your ear causes vibrates ear causes vibrates throughout your earthroughout your ear
What do Waves Do?What do Waves Do? Ex. Shock waves move Ex. Shock waves move the earth during an the earth during an earthquake.earthquake. Ex. Tsunami waves move Ex. Tsunami waves move anything in their pathanything in their path
Shock wave from breaking the Shock wave from breaking the sound sound barriorbarrior..
How a Wave TravelsHow a Wave Travels As wave travels in air, the As wave travels in air, the waves spread out in sphereswaves spread out in spheres the sphere will get bigger the sphere will get bigger and bigger as they move and bigger as they move farther awayfarther away
How a Wave TravelsHow a Wave Travels
Why is it more damaging to Why is it more damaging to your ears if you are your ears if you are standing next to a speaker standing next to a speaker rather than a 100 meters rather than a 100 meters away?away?
How a Wave TravelsHow a Wave Travels Each sphere carries the Each sphere carries the same amount of energysame amount of energy But the energy is more But the energy is more
spread outspread out
Speaker Sound waves
Vibrations and WavesVibrations and Waves Most waves are caused by Most waves are caused by a vibrating object, which a vibrating object, which will then cause other will then cause other objects to vibrate objects to vibrate Vibrations will transfer Vibrations will transfer energy from PE to KE.energy from PE to KE.
Vibrations and WavesVibrations and Waves simple harmonic motionsimple harmonic motion---- vibration would continue forevervibration would continue forever Damped harmonic motionDamped harmonic motion transfers the energy and the transfers the energy and the vibration will fade out.vibration will fade out. Ex. Shock absorbers on cars and Ex. Shock absorbers on cars and bikes.bikes.
Wave Vibration TypesWave Vibration Types 1. Transverse Waves1. Transverse Waves
--a wave that causes the particles of the a wave that causes the particles of the medium to vibrate perpendicular to medium to vibrate perpendicular to the direction of the wave.the direction of the wave. ““The WaveThe Wave”” at a stadium is a good at a stadium is a good illustration. illustration. Ex. Light wavesEx. Light waves
wave wave commericalcommerical
Wave Vibration TypesWave Vibration Types 2. Longitudinal Waves2. Longitudinal Waves
--a wave that causes the particles of a wave that causes the particles of the medium to vibrate parallel to the medium to vibrate parallel to the direction of the wave.the direction of the wave. they expand and compress.they expand and compress. Ex. Sound wavesEx. Sound waves
Wave Vibration TypesWave Vibration Types 3. Surface Waves3. Surface Waves
--waves that are both waves that are both transverse or longitudinal. transverse or longitudinal.
--Circular motionCircular motion --ex. Ocean wavesex. Ocean waves
Wave TypesWave Types
, or surface waves, or surface waves Electromagnetic (light):Electromagnetic (light):
--waves will only be transverse.waves will only be transverse.
Characteristics of Characteristics of WavesWaves
11.211.2
Wave PropertiesWave Properties all all transversetransverse waves have waves have similar shapes, no matter similar shapes, no matter the size of the wave. the size of the wave. The shape is called a The shape is called a sine curvesine curve or or sine wave. sine wave.
Sine WaveSine Wave
Wave PartsWave Parts CrestCrest Highest point of a Highest point of a transverse wavetransverse wave TroughTrough lowest point of a transverse lowest point of a transverse wavewave
Wave PartsWave Parts AmplitudeAmplitude
--The vertical distance that The vertical distance that particles vibrate from their particles vibrate from their normal position when a wave normal position when a wave passespasses measures the intensity of wave.measures the intensity of wave.
--ex.ex.
Wave PartsWave Parts WavelengthWavelength
--The distance between any two The distance between any two successive identical parts of a successive identical parts of a wavewave Represented by the symbol Represented by the symbol lambda (lambda (λλ)) Measured in a degree of metersMeasured in a degree of meters
Wave DiagramWave Diagram
Wave PropertiesWave Properties 1. Wavelength1. Wavelength
--measures the size of the measures the size of the wavewave
Wave PropertiesWave Properties 2. Amplitude2. Amplitude
--measures the intensity measures the intensity (strength) of the wave(strength) of the wave
Wave PropertiesWave Properties 3. Frequency3. Frequency
--the number of full wavelengths that the number of full wavelengths that pass a point in a particular period pass a point in a particular period of time (rate)of time (rate)
--Represented by the symbol (Represented by the symbol (ƒƒ)) --Measured in hertz (Hz) or beat/secMeasured in hertz (Hz) or beat/sec --Your radio dials are in megahertzYour radio dials are in megahertz
Wave PropertiesWave Properties 4. Period (time)4. Period (time)
--The The timetime
required for one full required for one full wavelength to pass a certain point wavelength to pass a certain point
--Represented by the symbol (T)Represented by the symbol (T) --Measured in secondsMeasured in seconds
Wavelength
High
Low
Low
High
Frequency, wavelength, Frequency, wavelength, and Periodand Period
Wavelength and period will Wavelength and period will increase when frequency increase when frequency decreases.decreases. λλ ↓↓, T, , T, ↓↓, then , then f f ↑↑
Frequency and PeriodFrequency and Period
You can calculate You can calculate frequency and period from frequency and period from each othereach other T=1/T=1/ff or or ff=1/T=1/T
Frequency and SoundFrequency and Sound We hear sounds from the We hear sounds from the range 20 Hz to 20,000 Hzrange 20 Hz to 20,000 Hz determines the determines the pitchpitch
Pitch and LoudnessPitch and Loudness
Frequency determines the energyFrequency determines the energy
Red is the easiest to see, violet is Red is the easiest to see, violet is the hottestthe hottest
Wave PropertiesWave Properties 5. Wave Speed5. Wave Speed --the speed at which a wave the speed at which a wave passes through a medium.passes through a medium.
--Waves travel at different Waves travel at different speeds in different media speeds in different media phases (s, l, g).phases (s, l, g).
Mechanical Wave SpeedMechanical Wave Speed These waves travel fastest These waves travel fastest in solids and the slowest in in solids and the slowest in gasesgases Why? (essay question)Why? (essay question)
sonic boom
Wave Speed EquationsWave Speed Equations Speed=wavelength/periodSpeed=wavelength/period v=v=λλ/T/T
Can also use:Can also use: Speed=frequency x wavelengthSpeed=frequency x wavelength v = v = ff x x λλ
ExamplesExamples A piano string vibrates with A piano string vibrates with a frequency of 264 Hz. If a frequency of 264 Hz. If the waves have a the waves have a wavelength of 1.3 m, what wavelength of 1.3 m, what is the speed of sound in air?is the speed of sound in air?
ExamplesExamples v= v= λλ ff
speed= (1.30 m) (264 Hz)speed= (1.30 m) (264 Hz) speed = 343 m/sspeed = 343 m/s
ExamplesExamples A string with aA string with a wavelength of 1.30 m andwavelength of 1.30 m and a period of 0.00379 s isa period of 0.00379 s is played. What is theplayed. What is the speed of the wave?speed of the wave?
ExamplesExamples V = V = λλ/T/T speed=1.30 m/0.00379 sspeed=1.30 m/0.00379 s speed = 343 m/sspeed = 343 m/s
Doppler EffectDoppler Effect an observed change in the an observed change in the frequency of a wave when the frequency of a wave when the source or observer is movingsource or observer is moving Object approaches with high Object approaches with high frequency but low wavelength, but frequency but low wavelength, but as it passes the frequency lowers as it passes the frequency lowers as the wavelength increasesas the wavelength increases
1. Reflection1. Reflection
The bouncing back of a The bouncing back of a wave as it meets a wave as it meets a surface or boundarysurface or boundary
InterferenceInterference Two types:Two types:
destructivedestructive
ConstructiveConstructive InterferenceInterference The crests of wave line up The crests of wave line up to combine their to combine their amplitudes making the amplitudes making the wave larger.wave larger. Wave becomes biggerWave becomes bigger
ConstructiveConstructive InterferenceInterference The new wave is The new wave is biggerbigger than the original when than the original when waves combinewaves combine
DestructiveDestructive InterferenceInterference When crest of one wave When crest of one wave meets the trough of another meets the trough of another wave wave Forms a Forms a smallersmaller wave than wave than the originalthe original
Interference of Light WavesInterference of Light Waves When light waves interfere When light waves interfere with each other, colorful with each other, colorful displays are produced.displays are produced. Soap bubblesSoap bubbles
Interference of Sound WavesInterference of Sound Waves When two waves with When two waves with different frequencies different frequencies interfere with each other, interfere with each other, beats are producedbeats are produced
Standing WavesStanding Waves wave that appears not to wave that appears not to move along the medium.move along the medium. two regionstwo regions
Standing WavesStanding Waves Regions of no vibrations Regions of no vibrations (nodes)(nodes) Regions of maximum Regions of maximum vibration vibration (antinodes)(antinodes)
Slide Number 13
WavesWaves A disturbance that A disturbance that transmits energy through transmits energy through matter or spacematter or space
WavesWaves Most waves move Most waves move through through mattermatter called a called a mediummedium.. Ex. Waves traveling Ex. Waves traveling through water. through water.
Types of WavesTypes of Waves 1. Mechanical Waves1. Mechanical Waves a wave that requires a a wave that requires a medium through which to medium through which to traveltravel Most type of wavesMost type of waves
Ex.Ex. Sound, seismicSound, seismic
Types of WavesTypes of Waves 2. Electromagnetic Waves2. Electromagnetic Waves waves caused by the waves caused by the disturbance in electric and disturbance in electric and magnetic fields and that magnetic fields and that does does not require a mediumnot require a medium..
(light radiation waves)(light radiation waves)
What do Waves Do?What do Waves Do? When waves travel When waves travel through media they are through media they are doing work (energy doing work (energy transferred). transferred). Ex. Sound traveling in your Ex. Sound traveling in your ear causes vibrates ear causes vibrates throughout your earthroughout your ear
What do Waves Do?What do Waves Do? Ex. Shock waves move Ex. Shock waves move the earth during an the earth during an earthquake.earthquake. Ex. Tsunami waves move Ex. Tsunami waves move anything in their pathanything in their path
Shock wave from breaking the Shock wave from breaking the sound sound barriorbarrior..
How a Wave TravelsHow a Wave Travels As wave travels in air, the As wave travels in air, the waves spread out in sphereswaves spread out in spheres the sphere will get bigger the sphere will get bigger and bigger as they move and bigger as they move farther awayfarther away
How a Wave TravelsHow a Wave Travels
Why is it more damaging to Why is it more damaging to your ears if you are your ears if you are standing next to a speaker standing next to a speaker rather than a 100 meters rather than a 100 meters away?away?
How a Wave TravelsHow a Wave Travels Each sphere carries the Each sphere carries the same amount of energysame amount of energy But the energy is more But the energy is more
spread outspread out
Speaker Sound waves
Vibrations and WavesVibrations and Waves Most waves are caused by Most waves are caused by a vibrating object, which a vibrating object, which will then cause other will then cause other objects to vibrate objects to vibrate Vibrations will transfer Vibrations will transfer energy from PE to KE.energy from PE to KE.
Vibrations and WavesVibrations and Waves simple harmonic motionsimple harmonic motion---- vibration would continue forevervibration would continue forever Damped harmonic motionDamped harmonic motion transfers the energy and the transfers the energy and the vibration will fade out.vibration will fade out. Ex. Shock absorbers on cars and Ex. Shock absorbers on cars and bikes.bikes.
Wave Vibration TypesWave Vibration Types 1. Transverse Waves1. Transverse Waves
--a wave that causes the particles of the a wave that causes the particles of the medium to vibrate perpendicular to medium to vibrate perpendicular to the direction of the wave.the direction of the wave. ““The WaveThe Wave”” at a stadium is a good at a stadium is a good illustration. illustration. Ex. Light wavesEx. Light waves
wave wave commericalcommerical
Wave Vibration TypesWave Vibration Types 2. Longitudinal Waves2. Longitudinal Waves
--a wave that causes the particles of a wave that causes the particles of the medium to vibrate parallel to the medium to vibrate parallel to the direction of the wave.the direction of the wave. they expand and compress.they expand and compress. Ex. Sound wavesEx. Sound waves
Wave Vibration TypesWave Vibration Types 3. Surface Waves3. Surface Waves
--waves that are both waves that are both transverse or longitudinal. transverse or longitudinal.
--Circular motionCircular motion --ex. Ocean wavesex. Ocean waves
Wave TypesWave Types
, or surface waves, or surface waves Electromagnetic (light):Electromagnetic (light):
--waves will only be transverse.waves will only be transverse.
Characteristics of Characteristics of WavesWaves
11.211.2
Wave PropertiesWave Properties all all transversetransverse waves have waves have similar shapes, no matter similar shapes, no matter the size of the wave. the size of the wave. The shape is called a The shape is called a sine curvesine curve or or sine wave. sine wave.
Sine WaveSine Wave
Wave PartsWave Parts CrestCrest Highest point of a Highest point of a transverse wavetransverse wave TroughTrough lowest point of a transverse lowest point of a transverse wavewave
Wave PartsWave Parts AmplitudeAmplitude
--The vertical distance that The vertical distance that particles vibrate from their particles vibrate from their normal position when a wave normal position when a wave passespasses measures the intensity of wave.measures the intensity of wave.
--ex.ex.
Wave PartsWave Parts WavelengthWavelength
--The distance between any two The distance between any two successive identical parts of a successive identical parts of a wavewave Represented by the symbol Represented by the symbol lambda (lambda (λλ)) Measured in a degree of metersMeasured in a degree of meters
Wave DiagramWave Diagram
Wave PropertiesWave Properties 1. Wavelength1. Wavelength
--measures the size of the measures the size of the wavewave
Wave PropertiesWave Properties 2. Amplitude2. Amplitude
--measures the intensity measures the intensity (strength) of the wave(strength) of the wave
Wave PropertiesWave Properties 3. Frequency3. Frequency
--the number of full wavelengths that the number of full wavelengths that pass a point in a particular period pass a point in a particular period of time (rate)of time (rate)
--Represented by the symbol (Represented by the symbol (ƒƒ)) --Measured in hertz (Hz) or beat/secMeasured in hertz (Hz) or beat/sec --Your radio dials are in megahertzYour radio dials are in megahertz
Wave PropertiesWave Properties 4. Period (time)4. Period (time)
--The The timetime
required for one full required for one full wavelength to pass a certain point wavelength to pass a certain point
--Represented by the symbol (T)Represented by the symbol (T) --Measured in secondsMeasured in seconds
Wavelength
High
Low
Low
High
Frequency, wavelength, Frequency, wavelength, and Periodand Period
Wavelength and period will Wavelength and period will increase when frequency increase when frequency decreases.decreases. λλ ↓↓, T, , T, ↓↓, then , then f f ↑↑
Frequency and PeriodFrequency and Period
You can calculate You can calculate frequency and period from frequency and period from each othereach other T=1/T=1/ff or or ff=1/T=1/T
Frequency and SoundFrequency and Sound We hear sounds from the We hear sounds from the range 20 Hz to 20,000 Hzrange 20 Hz to 20,000 Hz determines the determines the pitchpitch
Pitch and LoudnessPitch and Loudness
Frequency determines the energyFrequency determines the energy
Red is the easiest to see, violet is Red is the easiest to see, violet is the hottestthe hottest
Wave PropertiesWave Properties 5. Wave Speed5. Wave Speed --the speed at which a wave the speed at which a wave passes through a medium.passes through a medium.
--Waves travel at different Waves travel at different speeds in different media speeds in different media phases (s, l, g).phases (s, l, g).
Mechanical Wave SpeedMechanical Wave Speed These waves travel fastest These waves travel fastest in solids and the slowest in in solids and the slowest in gasesgases Why? (essay question)Why? (essay question)
sonic boom
Wave Speed EquationsWave Speed Equations Speed=wavelength/periodSpeed=wavelength/period v=v=λλ/T/T
Can also use:Can also use: Speed=frequency x wavelengthSpeed=frequency x wavelength v = v = ff x x λλ
ExamplesExamples A piano string vibrates with A piano string vibrates with a frequency of 264 Hz. If a frequency of 264 Hz. If the waves have a the waves have a wavelength of 1.3 m, what wavelength of 1.3 m, what is the speed of sound in air?is the speed of sound in air?
ExamplesExamples v= v= λλ ff
speed= (1.30 m) (264 Hz)speed= (1.30 m) (264 Hz) speed = 343 m/sspeed = 343 m/s
ExamplesExamples A string with aA string with a wavelength of 1.30 m andwavelength of 1.30 m and a period of 0.00379 s isa period of 0.00379 s is played. What is theplayed. What is the speed of the wave?speed of the wave?
ExamplesExamples V = V = λλ/T/T speed=1.30 m/0.00379 sspeed=1.30 m/0.00379 s speed = 343 m/sspeed = 343 m/s
Doppler EffectDoppler Effect an observed change in the an observed change in the frequency of a wave when the frequency of a wave when the source or observer is movingsource or observer is moving Object approaches with high Object approaches with high frequency but low wavelength, but frequency but low wavelength, but as it passes the frequency lowers as it passes the frequency lowers as the wavelength increasesas the wavelength increases
1. Reflection1. Reflection
The bouncing back of a The bouncing back of a wave as it meets a wave as it meets a surface or boundarysurface or boundary
InterferenceInterference Two types:Two types:
destructivedestructive
ConstructiveConstructive InterferenceInterference The crests of wave line up The crests of wave line up to combine their to combine their amplitudes making the amplitudes making the wave larger.wave larger. Wave becomes biggerWave becomes bigger
ConstructiveConstructive InterferenceInterference The new wave is The new wave is biggerbigger than the original when than the original when waves combinewaves combine
DestructiveDestructive InterferenceInterference When crest of one wave When crest of one wave meets the trough of another meets the trough of another wave wave Forms a Forms a smallersmaller wave than wave than the originalthe original
Interference of Light WavesInterference of Light Waves When light waves interfere When light waves interfere with each other, colorful with each other, colorful displays are produced.displays are produced. Soap bubblesSoap bubbles
Interference of Sound WavesInterference of Sound Waves When two waves with When two waves with different frequencies different frequencies interfere with each other, interfere with each other, beats are producedbeats are produced
Standing WavesStanding Waves wave that appears not to wave that appears not to move along the medium.move along the medium. two regionstwo regions
Standing WavesStanding Waves Regions of no vibrations Regions of no vibrations (nodes)(nodes) Regions of maximum Regions of maximum vibration vibration (antinodes)(antinodes)
Slide Number 13