1. Sound and Heat Sound 1 See an animation of transverse and longitudinal waves

2. Sound and Heat Sound 2 Transverse waves oscillate perpendicular to the direction of propagation. Properties: Wavelength amplitude speed propagation direction polarization λ A v x y

3. Sound and Heat Sound 3 Each point on a transverse wave oscillates perpendicular to the direction of propagation. Properties: period frequency amplitude polarization t T f = 1/T T A f

4. Sound and Heat Sound 4 Wave Equation Amplitude Wave Number Angular Frequency Propagation Direction Polarization Direction

5. Sound and Heat Sound 5 Properties: wavelength speed propagation direction λ y x v Longitudinal waves oscillate parallel to the direction of propagation. λ v x

6. Sound and Heat Sound 6 Each point on a longitudinal wave oscillates parallel to the direction of propagation. Properties: period frequency amplitude T y x v f = 1/T T A f

7. Sound and Heat Sound 7 Properties: wavelength speed propagation direction period frequency amplitude λ v x T A f Each property of a wave corresponds to a physical effect of sound. Effect: Pitch How long it takes the sound to reach you What direction the sound moves Also pitch Again this is pitch Volume Sound in air moves at about 768 mph (which is about 1 mile in 5 seconds). The frequency wavelength and period are related as follows. It is the frequency (period) that actually determines the pitch and it changes with speed.

8. Sound and Heat Sound 8 Guitar string change their frequency in three ways. 1. Different strings are made of different materials. Mike’s Fender guitar has three nylon strings Each of these has a different mass density,. The speed of sound from each string is given by the equation. The frequency is given by the equation, where the wavelength is related directly to the length of the string. and three metal strings

9. Sound and Heat Sound 9 Guitar string change their frequency in three ways. 2. Different strings have different amounts of tension on them. The speed of sound from each string is given by the equation. The frequency is given by the equation, where the wavelength is related directly to the length of the string. Increased tension means increased frequency.

10. Sound and Heat Sound 10 Guitar string change their frequency in three ways. The speed of sound from each string is given by the equation. The frequency is given by the equation, where the wavelength is related directly to the length of the string. Decreased length means increased frequency. 3. The length of the strings can be changed.

11. Sound and Heat Sound 11 Each string length will support many wavelengths. where m is any integer. The full “open” length of an acoustic guitar sting is 0.765 m

12. Sound and Heat Sound 12 Scientific Scientific designation Octave name Frequency (Hz) C -1 Subsubcontra8.176 C0C0 Subcontra16.352 C1C1 Contra32.703 C2C2 Great65.406 C3C3 Small130.813 C 4 (Middle C)One-lined261.626 C5C5 Two-lined523.251 C6C6 Three-lined1046.502 C7C7 Four-lined2093.005 C8C8 Five-lined4186.009 C9C9 Six-lined8372.018 C 10 Seven-lined16744.036 Designation by octave

13. Sound and Heat Sound 13 Graphic presentation Middle C in four clefsclefs Position of Middle C on an 88-key keyboardkeyboard

14. Sound and Heat Sound 14 44e′E4329.628High E 43 d ♯ ′/e ♭ ′D ♯ 4/E ♭ 4 311.127 42d′D4293.665DD 41 c ♯ ′/d ♭ ′C ♯ 4/D ♭ 4 277.183 40 c′ 1-line octave C4 Middle CMiddle C261.626 39bB3246.942B 38 a ♯ /b ♭ A ♯ 3/B ♭ 3 233.082 37aA3220.000A 36 g ♯ /a ♭ G ♯ 3/A ♭ 3 207.652 35gG3195.998GGG 34 f ♯ /g ♭ F ♯ 3/G ♭ 3 184.997 33fF3174.614 32eE3164.814 31 d ♯ /e ♭ D ♯ 3/E ♭ 3 155.563 30dD3146.832DD 29 c ♯ /d ♭ C ♯ 3/D ♭ 3 138.591 28c small octaveC3 Low CLow C130.813C 27BB2123.471 26 A ♯ /B ♭ A ♯ 2/B ♭ 2 116.541 25AA2110.000A 24 G ♯ /A ♭ G ♯ 2/A ♭ 2 103.826 23GG297.9989GG 22 F ♯ /G ♭ F ♯ 2/G ♭ 2 92.4986 21FF287.3071 20EE282.4069Low E Key numb er Helm holtz Helm holtz name Scient ific Scient ific name Frequ ency (Hz) Corresponding Open Strings ViolinViolaCelloBassGuitar

15. Sound and Heat Sound 15 The body of the guitar also changes the sound through resonance.