DONT REGRET MISSING OUT ON VALLEYFAIR

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DONT REGRET MISSING OUT ON VALLEYFAIR
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Reflection
Convex / Concave Mirrors Diffuse Reflections The
Reflection of Sound
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Convex Mirrors

• Mirrors that bulge out. Produce a virtual image
  that is smaller and closer to the mirror than the
  object is.

• http//www.edumedia-sciences.com/a309_l2-convex-mi
  rror.html

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Concave Mirrors
Now Im large enough to destroy the world! Mwa ha
ha!

• Mirrors that cave in. Produce a virtual image
  that is larger and farther away from the mirror
  than the object is (when the object is close to
  the mirror).

http//www.edumedia-sciences.com/a308_l2-concave-m
irror.html
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Diffuse Reflections

• The reflection of waves in many directions from a
  rough surface.
• Each ray obeys the law of reflection, but on a
  rough surface, there are many different angles.

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Is this a smooth surface?

• For light, this is a rough surface. But for
  long-wavelength radio waves, this is a polished
  surface. It is like a mirror to radio waves.
• The longer the wavelength, the more polished a
  rough surface looks.

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Reflection of Sound

• Sound is a wave, so it can be reflected.

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• Sound reflects better off of rigid and smooth
  surfaces. Sound energy that is not reflected is
  absorbed or transmitted.

• Reverberation the persistence of sound, as in an
  echo, due to multiple reflections.

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The Concert Hall

• Too much reverberation garbled sound
• Too much absorption quieter, duller sound.
• We want a balance between reverberation and
  absorption.
• Is it better to have smooth walls in a concert
  hall, or to have rough walls?

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The Concert Hall

• Want both!
• Grooves in the wall make sure that the sound a
  person hears is from many parts of the wall.
• Reflective surfaces are placed behind the stage
  to direct sound out to the audience.