Wave Behavior

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Wave Behavior

• Relfection, Refraction, Diffraction.

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Reflection

• Reflection occurs when a wave strikes an object
  and bounces off of it.
• All types of waves?including sound, water, and
  light waves?can be reflected

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Reflection

• When a wave bounces off a barrier or surface it
  is said to be reflected. How much of the wave
  that is reflected depends on the impedance
  between the two mediums.
• Impedance describes the difference in densities
  of the two mediums, the greater the difference in
  mediums, the greater the impedance.
• As the impedance increases, more of the wave's
  energy is reflected instead of being transmitted
  into the next medium.

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Echo

• Sometimes when the sound waves hit another
  object, they reflect off it and come back to you.
  
• Your ears hear the sound again, a few seconds
  after you first heard your footstep.

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Sonar

• How does a bat use reflection to find food?

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Law of Reflection

• The angle formed by the incident beam and the
  normal is the angle of incidence.
• The angle formed by the reflected beam and the
  normal is the angle of refection.
• According to the law of reflection, the angle of
  incidence is equal to the angle of refection.
  All reflected waves obey this law.

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Types of Reflection
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Refraction

• When a wave passes from one medium to
  another?such as when a light wave passes from air
  to water?it changes speed.
• If the wave is traveling at an angle when it
  passes from one medium to another, it changes
  direction, or bends, as it changes speed.

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Glass and light
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Refraction

• Refraction is the bending of a wave caused by a
  change in its speed as it moves from one medium
  to another.

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Sound refraction

• Sound wave will refract if there is a difference
  in air temperature.
• The different densities cause the waves to bend.

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Snells Law

• n1 index of refraction for incidence medium
• q1 angle of incidence
• n2 index of refraction for refractive medium
• q2 angle of refraction
• __________________________________________________
  _______________
• Speed of an EM wave in a Medium
• v c/n

The index of refraction is defined as the speed
of light in vacuum divided by the speed of light
in the medium.
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Critical Angle

• The angle of incidence that produces total
  internal reflection.

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Interference

• When waves appear at the same point in space and
  time and combine. (superposition)

Constructive
Destructive
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Diffraction

• Diffraction occurs when an object causes a wave
  to change direction and bend around it.
• Diffraction and refraction both cause waves to
  bend. The difference is that refraction occurs
  when waves pass through an object, while
  diffraction occurs when waves pass around an
  object.

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Diffraction
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