Celtic Harp
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Irish folk tunes
arranged by
Howard Baer |
Propagation of Waves
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Key Terms |
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Reflection |
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Refraction |
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Absorption |
Slide 3
Diffraction
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Diffraction is significant only when |
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D £ l |
Interference
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Interference occurs whenever two waves
occupy the same space at the same time. |
Resultant Wave
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The combined wave formed by the super-position
of two indi-vidual waves |
Constructive Interference
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The two interfering waves reinforce one
another |
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Occurs when the two waves are in phase |
Constructive Interference
Destructive Interference
Destructive Interference
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The two interfering waves cancel one
another |
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Occurs when the two waves are out of
phase |
Video I-3
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Interference: Transverse Waves on a String. |
Constructive Interference
– Waves
Destructive Interference
–
Waves
Constructive
Interference
(unequal amplitudes)
Destructive
Interference
(unequal amplitudes)
Sound From Two Sources
Sound From Two Sources
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Constructive interference occurs when |
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L1 - L2 = n l |
Sound From Two Sources
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Destructive interference occurs when |
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L1 - L2 = (n+ ½)l |
Video II-5
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Interference of Sound Waves |
Beats
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Occur when two waves of slightly
different frequency interfere |
Beats
Video II-6
Beat Frequency