WAVES

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WAVES

• WAVE INTERACTIONS

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FOUR WAYS WAVES INTERACT

• R-R-D-I
• REFLECTION
• REFRACTION
• DIFFRACTION
• INTERFERENCE

How waves interact with a medium
How waves interact with other waves
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LAW OF REFLECTION
Angle of incidence angle of reflection
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29.2 The Law of Reflection

• Incident rays and reflected rays make equal
  angles with a line perpendicular to the surface,
  called the normal.
• The angle between the incident ray and the normal
  is the angle of incidence.
• The angle between the reflected ray and the
  normal is the angle of reflection.
• Angle of incidence Angle of reflection

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29.4 Diffuse Reflection

• Diffuse reflection allows us to see most things
  around us.
• Light is diffusely reflected from paper in many
  directions.
• Light incident on a smooth mirror is only
  reflected in one direction.

Ordinary paper has a rough surface when viewed
with a microscope.
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29.8 Refraction of Light
As a light wave passes from air into water, its
speed decreases.
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31.1 Diffraction and Huygens Principle
The extent to which the water waves bend depends
on the size of the opening.
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CONCAVE AND CONVEX MIRRORS
Convex mirror causes light rays to converge.
Concave mirror causes light rays to diverge.
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REFLECTION

• The bouncing back of a wave when it meets a
  surface or boundary.
• http//www.gmi.edu/drussell/Demos/reflect/reflect
  .html
• http//www.physicsclassroom.com/mmedia/optics/lr.h
  tml

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REFRACTION

• The bending of a wave as it passes from one
  medium to another.
• http//www.physicsclassroom.com/mmedia/optics/lr.h
  tml

Light from pencil moves from air to your eye,
through water and glass to your eye, through
plastic to your eye
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Using diffraction gratings
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DIFFRACTION

• The bending of a wave as it passes through an
  opening or by an edge.
• Ex. Hear a voice from around the corner.
• http//www.pa.op.dlr.de/acoustics/essay1/beugung_e
  n.html
• http//www.infoline.ru/g23/5495/Physics/English/wa
  ves.htm

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INTERFERENCE

• The combination of two or more waves that exist
  in the same place at the same time.
• Constructive Interference (additive effectin
  phase)
• Destructive Interference (subtractive effectout
  of phase)
• http//users.erols.com/renau/wave_interference.htm
  l
• http//www2.biglobe.ne.jp/7Enorimari/science/Java
  Ed/e-wave3.html
• http//www2.biglobe.ne.jp/7Enorimari/science/Java
  Ed/e-wave2.html