Reflection, Diffraction, and Refraction

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Reflection, Diffraction, and Refraction

• How do waves behave when they hit a boundary,
  when they pass around an edge or opening, and
  when they pass from one medium to another?

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15-3-1 Reflection, Diffraction, and Refraction,
continued

• reflection the bouncing back of a ray of light,
  sound, or heat when the ray hits a surface that
  it does not go through

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15-3-2 Reflection, Diffraction, and Refraction,
continued

• Examples
• The reflection of light waves from a mirror or
  water waves reflected when they hit the side of a
  boat.

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15-3-3 Reflection, Diffraction, and Refraction ,
continued

• diffraction a change in the direction of a wave
  when the wave finds an obstacle or an edge, such
  as an opening

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15-3-4 Reflection, Diffraction, and Refraction ,
continued

• Examples
• Water waves diffract around a block in a tank of
  water and sound waves passing through a door
  diffract.

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15-3-5 Reflection, Diffraction, and Refraction ,
continued

• refraction the bending of a wavefront as the
  wavefront changes speed as it passes from one
  medium to another at an angle

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Interference

• What happens when two waves are in the same
  location?

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15-3-6 Interference

• interference the combination of two or more
  waves that results in a single wave

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15-3-7 Interference, continued

• constructive interference an increase in
  amplitude due to a superposition of two or more
  waves that produces an intensity equal to the sum
  of the intensities of the individual waves

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15-3-8 Interference, continued

• destructive interference a decrease in amplitude
  due to a superposition of two or more waves that
  produce an intensity equal to the difference of
  the intensities of the individual waves

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Interference, continued
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Standing Waves

• How are standing waves formed?

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15-3-10 Standing Waves

• standing wave a pattern of vibration that
  simulates a wave that is standing still

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15-3-11 Standing Waves, continued

• Each loop of a standing wave is separated from
  the next loop by points that have no vibration,
  called nodes.

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15-3-12 Standing Waves, continued

• Midway between the nodes lie points of maximum
  vibration, called antinodes.