Superposition

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Chapter 16

• Superposition
• and
• Standing Waves

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Section 16-1 Superposition of Waves
When two or more waves combine, the resultant
wave at any point, is the algebraic sum of the
individual waves.
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Superposition and the Wave Equation y3 c1y1
c2y2 superposition
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Interference of Harmonic Waves
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Constructive interference
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Destructive Interference
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Beats
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Phase difference due to a path difference
Waves are in phase if the phase difference, d
n(2p) This results in constructive interference
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The waves are exactly out of phase when d (n½)2p
This results in destructive interference
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Example 16-2 p 485
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Intensity versus path difference for two sources
that are in phase.
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Two sources that are in phase, or have a constant
phase difference are said to be coherent. The
Double Slit Experiment doubleslit
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Section 16-2 Standing Waves String fixed at both
ends
The standing wave condition is when L n(½?) and
fn n?/2L nf1
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A classic Steinway piano
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String fixed at one end.
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Wave functions for standing waves String fixed at
both ends wavesuperposition
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String fixed at one end
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Standing sound waves on the surface of the sun
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Some of the many modes of oscillation of a
ringing handbell