sound
DESCRIPTION
1. SOUND. intro. 2. Remember: Waves transport ENERGY. Sound Waves are Compressional waves . The vibrations of the molecules are parallel to the direction of the wave. Produced by the compressions and rarefaction of matter. 3. Sound Waves. 4. Sound Wave Propagation. - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/1.jpg)
SOUND SOUND
intro
11
Video Clip
![Page 2: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/2.jpg)
1) Recognize that all waves transfer energy.
3) Relate frequency &
wavelength to the
energy of different
types of electromagnetic
waves & mechanical
waves.
5) Compare and contrast the characteristics of electromagnetic and mechanical (sound)
waves.6) Explain the
phenomena of
reflection,
refraction,
interference, &
diffraction.
2) Explain the
Doppler Effect in
terms of everyday
interactions.
4) Relate the speed of sound to different mediums.
2
![Page 3: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/3.jpg)
Remember:Remember: Waves Waves
transport transport ENERGYENERGY
22
![Page 4: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/4.jpg)
Sound WavesSound Waves•Sound Waves are Compressional
waves.• The vibrations of the molecules are
parallel to the direction of the wave.
•Produced by the compressions and rarefaction of matter.
33
![Page 5: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/5.jpg)
Sound Wave Propagation
• Sound is produced by a Sound is produced by a vibrating object.vibrating object.• As one individual particle is disturbed,
it transmits the disturbance to the next interconnected particle.
• This disturbance continues to be passed on to the next particle.
• The result is that energy is transported without the actual transport of matter.
44
Clip
![Page 6: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/6.jpg)
![Page 8: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/8.jpg)
![Page 9: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/9.jpg)
Compressions are high density areas, and rarefactions are low density areas.
66
![Page 10: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/10.jpg)
• When a sound wave reaches the ear, a series of high and low pressure regions hit the eardrum.
• The arrival of a compression or high pressure region pushes the eardrum inward; the arrival of a low pressure regions serves to “pull” the eardrum outward.
• The continuous arrival of high and low pressure regions sets the eardrum into motion.
Eardrum
55
Video Clip
![Page 11: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/11.jpg)
99
![Page 12: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/12.jpg)
PitchPitch•Pitch is the highness or lowness of a sound.
• Clip
99
![Page 13: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/13.jpg)
Sound Activity
![Page 14: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/14.jpg)
Frequency and Frequency and PitchPitch• The frequency
of a sound wave determines the pitch.
• Pitch is the highness or lowness of a sound.
• The higher the frequency…the higher the pitch.
• Clip
99
![Page 15: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/15.jpg)
• Simulation (test tubes in lab activity examples)
![Page 16: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/16.jpg)
• Sound waves below 20 Hz are called infrasonic.
• Sounds waves above 20,000 Hz are called ultrasonic.
• Range of Human Hearing is from about 20 Hz –20,000 Hz
Low PitchLow Pitch
High High PitchPitch
1111
Review Clip
![Page 17: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/17.jpg)
BioacousticsBioacoustics • is a branch of science concerned
with the production of sound and its effects on living systems.
• Animals that generate “infrasound” include elephants, whales, alligators, hippos, rhinos, giraffe, lions, tigers and several birds. (whale)
• Animals that generate “ultrasound” include Dolphins, bats, many birds and insects.
1212
![Page 18: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/18.jpg)
EcholocationEcholocation•Bats send out sound waves using their mouth or nose.
•When the sound hits an object an echo comes back.
•They can the distance between themselves and the object
•They can identify an object by the sound of the echo.
• They can even tell the size, shape and texture of a tiny insect from its echo.
•Most bats use echolocation to navigate in the dark and find food. VIDEO
1313
![Page 19: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/19.jpg)
Animal Communication With Sound
1414
![Page 20: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/20.jpg)
Other uses of sound wavesSonar
1515
![Page 21: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/21.jpg)
Speed of SoundSpeed of Sound•Speed depends upon how fast
one particle can transfer its motion to another particle.
•Remember: Sound waves are mechanical waves.
•Speed of sound depends on the –medium–Temperature
•Why?
1616
![Page 22: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/22.jpg)
•Video Clip
1177
![Page 23: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/23.jpg)
1818 Faster in denser materials
![Page 24: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/24.jpg)
In which situation will the sound
travel the fastest?...slowest?
![Page 25: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/25.jpg)
In which material will the sound
travel the fastest?...slowest?
![Page 26: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/26.jpg)
What is causing
this change?
![Page 27: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/27.jpg)
LoudnessLoudness• Depends on the amplitude. Larger
amplitude means more pressure.
• Remember: amplitude is measure of the amount of energy in the wave.
• Sound level is measured in Decibels.
1199
![Page 28: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/28.jpg)
Which sound wave
would be the
loudest?
![Page 29: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/29.jpg)
• The energy transported by a wave is directly proportional to the square of the amplitude of the wave.
![Page 30: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/30.jpg)
2020
![Page 31: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/31.jpg)
Common Sounds in DecibelsSound Decibel Level
Listener's Perception
Whisper 10 Barely Audible
Quiet Conversation 30 Faintly Heard
Average Office 50 Moderate Level
Summer Nocturnal Insects
60 Moderate Level
Noisy Office 70 Loud
Average Street Traffic 85 Very Loud
Jackhammer 100 Extremely Loud
Jet Aircraft Taking Off 120 Physical Pain
2121
![Page 32: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/32.jpg)
2222
![Page 33: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/33.jpg)
• All sound consists of a waves.• If you add 2 waves together that
are going in the same direction, and if those waves are in phase--that is, the peaks and valleys of the waves line up--then the amplitude or height of the waves will double.
• Constructive InterferenceConstructive Interference
Wave Interactions2323
![Page 34: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/34.jpg)
• If you add 2 waves that are going in the same direction, and if those waves are completely out of phase--that is, the peaks of one line up with the valleys of the other--then the amplitude or height of the waves cancel each other out.
• Waves out of phase will cancel each other
Destructive InterferenceDestructive Interference
2424
![Page 35: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/35.jpg)
Video Clip
2525
![Page 36: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/36.jpg)
![Page 37: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/37.jpg)
Reflection of sound wavesEcho vs. Reverberation
• Sound waves can be reflected
• A reverberation is perceived when the reflected sound wave reaches your ear in less than 0.1 second after the original sound wave.
2626
![Page 38: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/38.jpg)
Tacoma Tacoma Narrows Bridge Narrows Bridge
CollapseCollapse
(Nov.7th 1940)
Galloping Galloping GertieGertie On a day of rather high winds, Gertie took on a 30-hertz transverse vibration (like sending waves down a rope by moving the end up and down) with an amplitude of 1½ feet! It later took on a twisting motion of about 14 hertz and quickly tore itself in two.
2727
![Page 39: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/39.jpg)
What’s causing the change in pitch?
![Page 40: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/40.jpg)
Doppler Doppler EffectEffect• Variation in the
perceived pitch of a sound due to a moving sound source.
• “bunches up “ in front of the source
• Spreads out behind the source
2828
![Page 41: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/41.jpg)
simulation
![Page 42: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/42.jpg)
Web Site Website
2929
![Page 43: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/43.jpg)
•a "sonic a "sonic boom" is the boom" is the sudden onset sudden onset and release of and release of pressure after pressure after the buildup by the buildup by the shock the shock wavewave
•ExampleExample
Sonic BoomSonic Boom3030
![Page 44: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/44.jpg)
3131
![Page 45: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/45.jpg)
Click on the Picture3232
![Page 46: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/46.jpg)
This picture shows a sonic boom created by the THRUST This picture shows a sonic boom created by the THRUST SSC team car as it broke the land speed record (and also SSC team car as it broke the land speed record (and also
broke the sound barrier on land).broke the sound barrier on land).
3333
![Page 47: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/47.jpg)
Sound Waves Review
![Page 48: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/48.jpg)
![Page 49: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/49.jpg)
3434
![Page 50: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/50.jpg)
““What’s wrong What’s wrong (or right) with (or right) with
these movies?”these movies?”
3535
![Page 51: SOUND](https://reader035.vdocuments.site/reader035/viewer/2022062408/56813cc9550346895da67269/html5/thumbnails/51.jpg)
Thanks to:• http://asa.aip.org/
• http://www.animalvoice.com/Links.htm
• http://www.indiana.edu/~emusic/acoustics/frequency.htm
• http://www.museumca.org/caves/onli_echo.html • http://www.everythingdolphins.com/SoundsPG.htm
• http://electron9.phys.utk.edu/phys135d/modules/m10/sound.htm