logging in or signing up Waves and Sound sunshine_qat Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 404 Category: Entertainment License: All Rights Reserved Like it (0) Dislike it (0) Added: March 19, 2010 This Presentation is Public Favorites: 1 Presentation Description No description available. Comments Posting comment... Premium member Presentation Transcript WAVES AND SOUND : WAVES AND SOUND Slide 2: Waves & Sound A. Waves 1. The nature of waves a. A wave is a rhythmic disturbance that transfers energy. b. All waves are made by something that vibrates. Slide 3: 2. Mechanical waves need a matter medium to travel through. (sound, water, seismic) 3. Two basic types of waves: a. Transverse b. Compressional (longitudinal) Slide 4: 4. Wave properties: a. Wavelength - distance from a point on a wave to the same corresponding point on the next wave. b. Frequency - number of waves that pass a point in one second (expressed in Hz). Slide 5: c. Wavelength has an inverse relationship to wave frequency. d. Wave velocity depends on the type of wave and medium. 1) Sound is faster in more dense media and in higher temps. 2) Light is slower in more dense media, but faster in a vacuum. Slide 6: 3) e. Amplitude - size related to the energy carried by the wave. 1) Transverse - how high above or how low below the nodal line. 2) Compressional - how dense the medium is at the compressions & rarefactions. Slide 7: 5. Wave behavior: a. Reflection - the bouncing back of a wave. 1) Sound echoes 2) Light images in mirrors 3) Law of reflection i = r Slide 8: b. Refraction - the bending of a wave caused by a change in speed as the wave moves from one medium to another. Slide 9: The girl sees the boy’s foot closer to the surface than it actually is. If the boy looks down at his feet, will they seem closer to him than they really are? No! He is looking straight down and not at an angle. There is no refraction for him. Slide 10: c. Diffraction - the bending of a wave around the edge of an object. 1) Water waves bending around islands 2) Water waves passing through a slit and spreading out Slide 11: 3) Diffraction depends on the size of the obstacle or opening compared to the wavelength of the wave. Less occurs if wavelength is smaller than the object. More occurs if wavelength is larger than the object. Slide 12: 4) AM radio waves are longer and can diffract around large buildings and mountains; FM can’t. Slide 13: d. Interference - two or more waves overlapping to form a new wave. Slide 14: 1) Constructive (in phase) Sound waves that constructively interfere are louder Slide 15: 2) Destructive (out of phase) Sound waves that destructively interfere are not as loud Slide 16: e. Standing wave - a wave pattern that occurs when two waves equal in wavelength and frequency meet from opposite directions and continuously interfere with each other. node antinode Slide 17: f. Resonance - the ability of an object to vibrate by absorbing energy at its natural frequency. Slide 18: B. Sound 1. Energy is transferred from particle to particle through matter. 2. How we hear a. Outer ear collects sound. b. Middle ear amplifies sound. c. Inner ear converts sound. Slide 20: 3. Properties of sound a. Intensity and loudness 1) Intensity depends on the energy in a sound wave. 2) Loudness is human perception of intensity. 3) Loudness is measured on the decibel scale. Slide 21: a) Threshold of hearing (0 db) b) Threshold of pain (120 db) Slide 22: b. Frequency and pitch 1) High frequency means more vibrations hitting the ear. 2) Pitch is how high or how low a sound seems to be. 3) Healthy humans can hear from 20 Hz to 20,000 Hz 4) We are most sensitive from 440 Hz to 7,000 Hz. Slide 23: 5) Ultrasonic sound has a frequency greater than 20,000 Hz. a) Dogs (up to 35,000 Hz) b) Bats (over 100,000 Hz) c) Medical diagnosis 6) Infrasonic sound has a frequency below 20 Hz; they are felt rather than heard (earthquakes, heavy machinery). Slide 24: c. Speed of sound 1) 332 m/s in air at 0 C. 2) Changes by 0.6 m/s for every Celsius degree from 0 C. 3) Subsonic – slower 4) Supersonic – faster than sound (Mach 1 = speed of sound) 5) Sonic boom (pressure cone) Slide 25: d. The Doppler effect – the change in pitch due to a moving wave source. 1) Objects moving toward you cause a higher pitched sound. 2) Objects moving away cause sound of lower pitch. 3) Used in radar by police and meteorologists and in astronomy. Slide 27: 4. Musical sound a. Noise has no pattern. b. Music has a pattern and deliberate pitches. c. Sound quality describes differences of sounds that have the same pitch and loudness. d. Every instrument has its own set of overtones. Slide 28: e) Beats are pulsing variations of loudness caused by interference of sounds of slightly different frequencies. Slide 29: 5. Uses of sound a. Acoustics – the study of sound. Soft materials dampen sound; hard materials reflect it (echoes and reverberations). b. SONAR – Sound Navigation and Ranging (echolocation). c. Ultrasound imaging d. Kidney stones & gallstones. You do not have the permission to view this presentation. In order to view it, please contact the author of the presentation.
Waves and Sound sunshine_qat Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 404 Category: Entertainment License: All Rights Reserved Like it (0) Dislike it (0) Added: March 19, 2010 This Presentation is Public Favorites: 1 Presentation Description No description available. Comments Posting comment... Premium member Presentation Transcript WAVES AND SOUND : WAVES AND SOUND Slide 2: Waves & Sound A. Waves 1. The nature of waves a. A wave is a rhythmic disturbance that transfers energy. b. All waves are made by something that vibrates. Slide 3: 2. Mechanical waves need a matter medium to travel through. (sound, water, seismic) 3. Two basic types of waves: a. Transverse b. Compressional (longitudinal) Slide 4: 4. Wave properties: a. Wavelength - distance from a point on a wave to the same corresponding point on the next wave. b. Frequency - number of waves that pass a point in one second (expressed in Hz). Slide 5: c. Wavelength has an inverse relationship to wave frequency. d. Wave velocity depends on the type of wave and medium. 1) Sound is faster in more dense media and in higher temps. 2) Light is slower in more dense media, but faster in a vacuum. Slide 6: 3) e. Amplitude - size related to the energy carried by the wave. 1) Transverse - how high above or how low below the nodal line. 2) Compressional - how dense the medium is at the compressions & rarefactions. Slide 7: 5. Wave behavior: a. Reflection - the bouncing back of a wave. 1) Sound echoes 2) Light images in mirrors 3) Law of reflection i = r Slide 8: b. Refraction - the bending of a wave caused by a change in speed as the wave moves from one medium to another. Slide 9: The girl sees the boy’s foot closer to the surface than it actually is. If the boy looks down at his feet, will they seem closer to him than they really are? No! He is looking straight down and not at an angle. There is no refraction for him. Slide 10: c. Diffraction - the bending of a wave around the edge of an object. 1) Water waves bending around islands 2) Water waves passing through a slit and spreading out Slide 11: 3) Diffraction depends on the size of the obstacle or opening compared to the wavelength of the wave. Less occurs if wavelength is smaller than the object. More occurs if wavelength is larger than the object. Slide 12: 4) AM radio waves are longer and can diffract around large buildings and mountains; FM can’t. Slide 13: d. Interference - two or more waves overlapping to form a new wave. Slide 14: 1) Constructive (in phase) Sound waves that constructively interfere are louder Slide 15: 2) Destructive (out of phase) Sound waves that destructively interfere are not as loud Slide 16: e. Standing wave - a wave pattern that occurs when two waves equal in wavelength and frequency meet from opposite directions and continuously interfere with each other. node antinode Slide 17: f. Resonance - the ability of an object to vibrate by absorbing energy at its natural frequency. Slide 18: B. Sound 1. Energy is transferred from particle to particle through matter. 2. How we hear a. Outer ear collects sound. b. Middle ear amplifies sound. c. Inner ear converts sound. Slide 20: 3. Properties of sound a. Intensity and loudness 1) Intensity depends on the energy in a sound wave. 2) Loudness is human perception of intensity. 3) Loudness is measured on the decibel scale. Slide 21: a) Threshold of hearing (0 db) b) Threshold of pain (120 db) Slide 22: b. Frequency and pitch 1) High frequency means more vibrations hitting the ear. 2) Pitch is how high or how low a sound seems to be. 3) Healthy humans can hear from 20 Hz to 20,000 Hz 4) We are most sensitive from 440 Hz to 7,000 Hz. Slide 23: 5) Ultrasonic sound has a frequency greater than 20,000 Hz. a) Dogs (up to 35,000 Hz) b) Bats (over 100,000 Hz) c) Medical diagnosis 6) Infrasonic sound has a frequency below 20 Hz; they are felt rather than heard (earthquakes, heavy machinery). Slide 24: c. Speed of sound 1) 332 m/s in air at 0 C. 2) Changes by 0.6 m/s for every Celsius degree from 0 C. 3) Subsonic – slower 4) Supersonic – faster than sound (Mach 1 = speed of sound) 5) Sonic boom (pressure cone) Slide 25: d. The Doppler effect – the change in pitch due to a moving wave source. 1) Objects moving toward you cause a higher pitched sound. 2) Objects moving away cause sound of lower pitch. 3) Used in radar by police and meteorologists and in astronomy. Slide 27: 4. Musical sound a. Noise has no pattern. b. Music has a pattern and deliberate pitches. c. Sound quality describes differences of sounds that have the same pitch and loudness. d. Every instrument has its own set of overtones. Slide 28: e) Beats are pulsing variations of loudness caused by interference of sounds of slightly different frequencies. Slide 29: 5. Uses of sound a. Acoustics – the study of sound. Soft materials dampen sound; hard materials reflect it (echoes and reverberations). b. SONAR – Sound Navigation and Ranging (echolocation). c. Ultrasound imaging d. Kidney stones & gallstones.