Presentation is loading. Please wait.

Presentation is loading. Please wait.

THE PHYSICS OF MUSIC ♫. MUSIC Musical Tone- Pleasing sounds that have periodic wave patterns. Quality of sound- distinguishes identical notes from different.

Similar presentations


Presentation on theme: "THE PHYSICS OF MUSIC ♫. MUSIC Musical Tone- Pleasing sounds that have periodic wave patterns. Quality of sound- distinguishes identical notes from different."— Presentation transcript:

1 THE PHYSICS OF MUSIC ♫

2 MUSIC Musical Tone- Pleasing sounds that have periodic wave patterns. Quality of sound- distinguishes identical notes from different instruments. http://www.animations.physics.unsw.edu. au/jw/sound-pitch-loudness-timbre.htm

3 Beats- the change in sound intensity due to the interference of sound. Beat Frequency- the number of maximum intensity points per second. 2 beats

4 Ex. A sound with a frequency of 400Hz interferes with a second sound. If this produces 20 beats in 5.0 seconds, what is the frequency of the second sound? BF= 20beats/ 5 sec = 4 beats/sec 4 beats/sec = | 400Hz- f 2 | = 396Hz or 404Hz BF = # beats or BF = | f 1 – f 2 | second

5 STANDING WAVES Two identical waves traveling in opposite directions. N –node A- antinode

6 MODES OF VIBRATION Fundamental mode, lowest pitch. λ = 2L First overtone, second harmonic, λ = L Second overtone, 3 rd harmonic, λ = 2/3L Third overtone, 4 th harmonic, λ = 1/2L

7 HARMONICS Whole number multiples of the fundamental frequency. Doubling the frequency will raise the pitch one octave (8 notes)

8 String Instruments

9 LAWS OF STRINGS  Law of Length: As the length of a string increases, frequency and pitch decreases.  Law of Diameter: As the diameter of a string increases, frequency decreases.

10  Law of Tension: As the tension on a string increases, frequency and pitch increases.  Law of Density: If a more dense string is used, the frequency and pitch decreases.

11 Woodwind and Brass Use resonating air columns to make music.

12 RESONANCE IN AIR COLUMNS Resonance occurs every half wavelength.

13 λ = 2L f 1 = v/2L L

14 λ = L f 2 = v/L L

15 λ = 2/3L f 3 =3v/2L L

16 Wavelength depends of the length and diameter of the resonating pipe. λ = 2( L + 0.8d) L- length (m) d- diameter (m)

17 Ex: An open plastic pipe will resonate at its lowest frequency when a tuning fork is held over it. A)If the pipe has a length of 60cm and a diameter of 4.0cm what is the wavelength? λ = 2( L + 0.8d) λ = 2(0.6m + 0.8(0.04m) λ = 1.264m

18 B) If the sound produced has a speed of 342m/s, what is its frequency? (Lowest frequency is the 1 st harmonic.) f 1 = v/2L f 1 = 342m/s / (2 x 0.6m) f 1 = 285 Hz

19 Just for fun! The Rubens Tube http://www.youtube.com/watch?v=gpCquU WqaYwhttp://www.youtube.com/watch?v=gpCquU WqaYw http://www.youtube.com/watch?v=M- 021bsxM_k


Download ppt "THE PHYSICS OF MUSIC ♫. MUSIC Musical Tone- Pleasing sounds that have periodic wave patterns. Quality of sound- distinguishes identical notes from different."

Similar presentations


Ads by Google