LIGHT AND OPTICS

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LIGHT AND OPTICS

• C. Smith
• IPC

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LIGHT AND OPTICS

• 1. EXPLAIN THE RELATIONSHIP AMONG RADIANT
  ENERGY, ELECTROMAGNETIC SPECTRUM AND VISIBLE
  LIGHT.
• RADIANT ENERGY - ENERGY TRANSFERRED THROUGH
  SPACE BY ELECTROMAGNETIC WAVES
• ELECTROMAGNETIC SPECTRUM -
• - ALL OF THE WAVES THAT APPROACH THE EARTH FROM
  SPACE
• - ALL TRAVEL AT THE SAME SPEED (SPEED OF LIGHT)

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LIGHT AND OPTICS

• - ALL DIFFER IN WAVELENGTH AND FREQUENCY
• COSMIC SHORTEST WAVELENGTH
• GAMMA HIGHEST FREQUENCY
• X-RAYS
• ULTRAVIOLET
• VISIBLE LIGHT
• INFRARED
• MICROWAVES LONGEST WAVELENGTH
• RADIO WAVES LOWEST FREQUENCY

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LIGHT AND OPTICS

• VISIBLE LIGHT - THAT PART OF THE EM SPECTRUM THAT
  HUMANS CAN SEE
• - ROYGBIV
• - RED HAS THE LONGEST WAVELENGTH
• - VIOLET HAS THE SHORTEST WAVELENGTH

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LIGHT AND OPTICS

• 2. EXPLAIN THE DIFFERENCE AMONG TRANSPARENT,
  TRANSLUCENT AND OPAQUE.
• TRANSPARENT - MOST LIGHT CAN PASS THROUGH - CLEAR
  IMAGE
• TRANSLUCENT - SOME LIGHT CAN PASS THROUGH -
  BLURRY IMAGE
• OPAQUE - NO LIGHT CAN PASS THROUGH - NO IMAGE

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LIGHT AND OPTICS

• 3. STATE THE SPEED OF LIGHT IN A VACUUM.
• SPEED OF LIGHT IS 3 x 108 ms/ OR 300,000,000 m/s
• 4. DEFINE REFLECTION.
• REFLECTION - THE BOUNCING OF A LIGHT RAY FROM A
  SURFACE.

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LIGHT AND OPTICS

• 5. STATE THE LAW OF REFLECTION.
• LAW OF REFLECTION- THE ANGLE OF INCIDENCE EQUALS
  THE ANGLE OF REFLECTION N
• IR RR ? I ? R
• MIRROR
• IR INCIDENT RAY
• RR REFLECTED RAY
• N NORMAL
• ? I ANGLE OF INCIDENCE
• ? R ANGLE OF REFLECTION

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LIGHT AND OPTICS

• 6. COMPARE HOW LIGHT IS REFLECTED FROM SMOOTH AND
  ROUGH SURFACES.
• IF PARALLEL LIGHT RAYS STRIKE A SMOOTH SURFACE,
  THE LIGHT RAYS ARE REFLECTED PARALLEL.
• IF PARALLEL LIGHT RAYS STRIKE A ROUGH SURFACE,
  THE LIGHT RAYS ARE SCATTERED.
• 7. DEFINE IMAGE.
• IMAGE -A COPY OF AN OBJECT, FORMED BY A MIRROR OR
  LENS

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LIGHT AND OPTICS

• 8. TELL THE DIFFERENCE BETWEEN REAL AND VIRTUAL
  IMAGES.
• REAL IMAGES - REFLECTED RAYS CROSS AND FOCUS- IT
  ACTUALLY EXISTS WHERE IT APPEARS
• VIRTUAL IMAGE - REFLECTED RAYS DO NOT CROSS AND
  FOCUS- IMAGE IS NOT WHERE IT APPEARS TO BE

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LIGHT AND OPTICS

• 9. DESCRIBE THE IMAGE FORMED BY A PLANE MIRROR.
• A PLANE MIRROR IS A FLAT MIRROR. A PLANE MIRROR
  FORMS AN IMAGE THAT IS...
• VIRTUAL
• UPRIGHT
• REVERSED
• SAME SIZE AS OBJECT
• EQUAL DISTANCE BEHIND MIRROR AS OBJECT IS IN
  FRONT OF MIRROR

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LIGHT AND OPTICS

• 10. DESCRIBE AND COMPARE CONCAVE AND CONVEX
  MIRRORS.
• CONCAVE MIRROR - CURVES IN AT THE CENTER
• - USED AS FLASHLIGHT REFLECTORS
• - CAUSES PARALLEL LIGHT RAYS TO CROSS AND FOCUS
• AT THE FOCAL POINT- PRODUCES A REAL IMAGE

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LIGHT AND OPTICS
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LIGHT AND OPTICS

• CONVEX MIRROR - CURVES OUT AT THE CENTER
• - USED TO SEE A LARGER AREA
• - CAUSES PARALLEL LIGHT RAYS TO SCATTER
• - PRODUCES A VIRTUAL IMAGE

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LIGHT AND OPTICS
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LIGHT AND OPTICS

• 11. EXPLAIN THE DIFFERENCE AMONG REFRACTION,
  DIFFRACTION, AND POLARIZATION.
• REFRACTION - THE BENDING OF A LIGHT RAY. THE RAY
  BENDS BECAUSE ITS SPEED CHANGES
• THE SPEED CHANGES BECAUSE THE MEDIUMS HAVE
  DIFFERENT DENSITIES
• MORE DENSE SLOWER - LIGHT TRAVELS FASTEST IN A
  VACUUM, SLOWER IN AIR, SLOWER IN LIQUIDS AND
  SLOWEST IN SOLIDS

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LIGHT AND OPTICS

• ?i ?i

glass
glass
air
air
? r ? r
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LIGHT AND OPTICS

• AS A LIGHT RAYS PASSES FROM AIR TO GLASS, IT
  SLOWS DOWN AND BENDS TOWARD THE NORMAL.
• AS A LIGHT RAYS PASSES FROM GLASS TO AIR IT
  SPEEDS UP AND BENDS AWAY FROM THE NORMAL.

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LIGHT AND OPTICS

• DIFFRACTION - LIGHT SPREADING AS IT PASSES
  THROUGH A SMALL OPENING OR AROUND A SMALL OBJECT
• THIS SPREADING CAUSES INTERFERENCE, WHICH
  CAUSES A BREAKDOWN OF LIGHT INTO THE PARTS OF
  THE VISIBLE SPECTRUM

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LIGHT AND OPTICS

• POLARIZAITON - PRODUCING LIGHT WITH
  ELECTROMAGNETIC VIBRATIONS IN ONLY ONE DIRECTION.
  
• A SUBSTANCE THAT CAUSES POLARIZATON OF LIGHT IS
  CALLED A POLARIZING FILTER.

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LIGHT AND OPTICS

• 12. STATE THE LAW OF REFRACTION.
• AS A LIGHT RAYS PASSES FROM A LESS DENSE MEDIUM
  TO A MORE DENSE MEDIUM, THE RAY WILL BEND TOWARD
  THE NORMAL.
• AS A LIGHT RAYS PASSES FROM A MORE DENSE MEDIUM
  TO A LESS DENSE MEDIUM, IT WILL BEND AWAY FROM
  THE NORMAL.

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LIGHT AND OPTICS

• 13. DESCRIBE CONCAVE AND CONVEX LENSES.
• CONCAVE LENS - THIN IN THE CENTER- THICK AT THE
  EDGES
• ALSO CALLED A DIVERGING LENS - CAUSES PARALLEL
  LIGHT RAYS TO SPREAD OUT
• CONVEX LENS - THICK IN THE CENTER- THIN AT THE
  EDGE
• - ALSO CALLED A CONVERGING LENS- CAUSES PARALLEL
  LIGHT RAYS TO COME TOGETHER

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LIGHT AND OPTICS
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LIGHT AND OPTICS

• 14. LIST AND DESCRIBE THE PARTS OF THE EYE.
• CORNEA - CLEAR PROTECTING COATING
• PUPIL - SMALL OPENING TO THE EYE
• IRIS - COLORED ROUND CIRCLE AROUND THE PUPIL-
  REGULATES THE SIZE OF THE PUPIL
• LENS - CONVEX, FOCUSES IMAGE ON RETINA
• RETINA - BACK WALL OF EYE WHERE IMAGE IS FOCUSED

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LIGHT AND OPTICS

• 15. DESCRIBE HOW LENSES HELP OUR EYESIGHT.
• MYOPIA - ALSO CALLED NEARSIGHTED - PERSON CAN SEE
  NEAR BUT NOT FAR
• - EYEBALL TOO LONG
• - WEAR CONCAVE LENSES
• HYPEROPIA -- ALSO CALLED FARSIGHTED - PERSON CAN
  SEE FAR BUT NOT NEAR
• - EYEBALL TOO SHORT
• - WEAR CONVEX LENSES

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LIGHT AND OPTICS

• 16. LIST THE FACTORS THAT DETERMINE THE COLOR OF
  AN OBJECT.
• THE COLOR OF AN OBJECT IS DETERMINED BY ...
• THE COLORS THAT STRIKE THE OBJECT
• THE COLORS ABSORBED BY THE OBJECT
• THE COLORS REFLECTED BY THE OBJECT

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LIGHT AND OPTICS

• 17. IDENTIFY THE PRIMARY AND SECONDARY COLORS OF
  LIGHT.
• THE PRIMARY COLORS ARE RED, BLUE AND GREEN.
• THE SECONDARY COLORS ARE YELLOW, CYAN AND MAGENTA.

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LIGHT AND OPTICS
RED BLUE MAGENTA BLUE GREEN CYAN RED
GREEN YELLOW
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LIGHT AND OPTICS

• 18. TELL THE DIFFERENCE BETWEEN COLOR ADDITION
  AND COLOR SUBTRACTION.
• COLOR ADDITION - COLORS ARE COMBINED TO FORM A
  NEW COLOR
• COLOR SUBTRACTION - COLORS ARE ABSORBED TO FORM A
  NEW COLOR