LIGHT AND COLOUR

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LIGHT AND COLOUR
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LINK TO INTERACTIVE SITE CLICK HERE
http//micro.magnet.fsu.edu/primer/java/reflection
/index.html
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Angle of incidence angle of reflection
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THE LAW OF REFLECTION

• The angle of incidence is equal to the angle of
  reflection.
• The image in a plane mirror is virtual and is the
  same size as the object.

• Plane mirrors are used in periscopes.
• They are used in rear view mirrors.
• The image is as far behind the mirror is as the
  object is in front.
• Image is laterally inverted

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PERISCOPES
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Shiny smooth surfaces reflect regularly, other
surfaces also reflect light but if the surface is
rough the light is reflected in all directions.
We call this diffuse reflection.
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Diffuse Reflection
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CONVEX AND CONCAVE MIRRORS
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http//micro.magnet.fsu.edu/primer/java/mirrors/co
ncave.html
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Convex and Concave Mirrors

• A concave mirror is a converging mirror. Parallel
  rays of light are reflected through the focal
  point of a concave mirror.
• A convex mirror is a diverging mirror. Parallel
  rays of light are reflected so that they appear
  to come from the focal point of a convex mirror.

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Molecular Expressions Microscopy Primer Light
and Color - Concave Mirrors Interactive Java
Tutorial
http//micro.magnet.fsu.edu/primer/java/mirrors/co
nvex.html
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Uses of Concave Mirrors

• Used to collect light energy, sound, heat,
  radiation, radar and TV signals.
• If you move close to a concave mirror, then you
  see a magnified image of yourself. This image is
  upright and virtual as well as magnified. Shaving
  and make up mirrors

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Uses of Convex Mirrors

• They always produce virtual upright images.
• The image is always smaller than the object.
• They are useful when you want a wide field of
  view car driving mirrors or shop security.

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Refraction

• This is the bending of light rays
• Happens because the rays change speed.
• When they enter a more dense medium (glass,
  water,) they slow down.
• When they enter a less dense medium like air,
  they speed up.

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http//micro.magnet.fsu.edu/primer/java/refraction
/index.html
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http//micro.magnet.fsu.edu/primer/java/variablele
ns/index.html
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Total internal reflectionand refraction

• When an object is viewed through water the image
  we see is changed because of the way light waves
  behave as they pass from the water into the air.

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CLICK HERE FOR INTERACTIVE SITE
http//micro.magnet.fsu.edu/primer/java/refraction
/fishtank/index.html
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COLOUR

• White light is made up of the seven colours of
  the rainbow.
• Red, orange, yellow, green, blue, indigo, and
  violet.

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Molecular Expressions Microscopy Primer Light
and Color - Refraction of Light
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Molecular Expressions Microscopy Primer Light
and Color - Subtractive Colors
Molecular Expressions Microscopy Primer - Light
and Color - Additive Primary Colors
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How We See Colour

• We see colours because those are refelected off
  and object. Yellow light is refelected to our
  eyes but the other colours are absorbed so we see
  yellow.

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RAINBOWS

• We see rainbows because the light is first
  refracted by the raindrop and then reflected off
  the back of the raindrop.

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MIXING COLOURS

• When we mix the three primary colours of light we
  get white light. RED GREEN BLUE
• If we mix the three secondary colours of light we
  get black CYAN MAGENTA YELLOW

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In white light in red light in green light in
blue light this is what the grapes and card will
look like
Molecular Expressions Microscopy Primer Light
and Color - Color Filters Interactive Java
Tutorial
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In these glasses only light perpendicular to the
highway is allowed through. This halves the
amount of light reaching the eye.
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THE EYE

• The pupil allows light to enter the eye.
• The lens helps to focus the light
• Light sensitive cells in the retina detect the
  light.
• A nerve impulse travels from the retina to the
  brain along the optic nerve where it is
  interpreted.
• The iris helps to change the size of the pupil

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Molecular Expressions Microscopy Primer Light
and Color - Human Vision Interactive Java
Tutorial
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http//cse.ssl.berkeley.edu/light/program.html
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CLICK HERE TO INVESTIGATE REFRACTION IN A PRISM
http//micro.magnet.fsu.edu/primer/java/prismsandb
eamsplitters/equilateralprism/index.html