Chapter-15 Making Waves

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Chapter-15 Making Waves
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Objectives

1. To investigate the basic nature of waves and
   their properties.
2. Wave Properties Speed, Wavelength, Frequency,
   and Period.
3. Wave Phenomena Reflection, Interference, and
   Transmission.
4. Waves on a string, sound waves, music, and
   Doppler effect.

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Ocean Waves
Wave is a traveling disturbance. Wave carries
energy from place to place.
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Types of waves
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Transverse waves
A transverse wave is one in which the disturbance
is perpendicular to the direction of travel of
the wave. Examples Light wave, waves on a guitar
string.
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Longitudinal Waves
Longitudinal wave is one in which the disturbance
is parallel to the line of travel of the wave.
Example Sound wave in air is a longitudinal
wave.
Q8
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What is a periodic wave?
Periodic waves are waves that repeat.
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Amplitude, Wavelength, and Period
The amplitude, A is the maximum disturbance.
The wavelength, ?  is the horizontal length of
one cycle of the wave. The period, T is the time
required for one complete up/down cycle of the
wave.
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Frequency and Period
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Wave Speed
E2
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Waves on a Rope
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Periodic Wave
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Harmonic Wave
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The Speed of Wave on a String
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Guitar
The strings on a steel-string guitar have
different weights, µ m/L.
Q13
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Principle of Superposition
When two or more waves are present simultaneously
at the same place, the resultant disturbance is
the sum of the disturbances from the individual
waves.
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Constructive Interference of Sound Waves
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Destructive Interference
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Standing Waves
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Nodes and Antinodes
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What determines the frequency of a wave on a
guitar string?
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Longitudinal Standing Waves
Musical instruments in the wind family depend on
longitudinal standing waves in producing sound.
Since wind instruments (trumpet, flute, clarinet,
pipe organ, etc.) are modified tubes or columns
of air, it is useful to examine the standing
waves that can be set up in such tubes.
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Standing-Wave Patterns
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Doppler Effect