2. Physics Review Refraction Topic Slides Minutes Displacement Vectors1
Displacement 9 27 2
Vectors 13 39 3
Kinematics 4
Graphs 10 30 5
Energy 6
Power 15 7
Springs 12 8
Shadows
Field of Vision 21
Colors 11
Concave mirrors
Convex mirrors 14
Lenses
Optical Power 18
Refraction

3. Refraction
Refraction is the bending of light rays as they pass from one
medium into another medium of different optical density.
The index of refraction of a transparent medium is a ratio of the
speed of light in a vacuum to the speed of light in the medium:
n = c/v where n = is the index of refraction (no units)
c = 3 x 108 m/s
v = speed of light in the medium (in m/s)
Note : The greater the index of refraction of a medium, the slower light travels in that medium. The index of refraction for a vacuum is 1, for water it is 1.33, for diamond it is 2.42, etc.
The highest of any natural material
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4. Refraction
When refraction occurs, light bends away from the normal when the
optical density (index of refraction) is less dense (and vice versa).
The following illustration demonstrates this fact:
n1 = 1
Normal
n1 = 1.5
Normal
n2 = 1.5
n2 = 1
n1 < n2
n1 > n2
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5. PRACTICE
Old ex-12 Component Forces Part-2/2

6. Refraction Slide:
13. 1
A light ray passes from air into a liquid as illustrated below.
Determine the index of refraction for this liquid.
Step-1: Determine the angle of incidence and the angle of refraction. i r
Step-2: Calculate the index of refraction using Snell’s Law.
A) 1.5
B) 1.4
C) 0.72
D) 0.65
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7. Refraction Slide:
13. 2
Use Snell's Law
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8. 13. 3
Refraction Slide:
Answer
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9. Refraction Slide:
13. 4
Away from
normal
Away from
normal
Towards
normal
Away from
normal
Because n is greater than n , the refracted ray
bends AWAY from the normal. 1 2
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10. Critical angle means the angle of refraction is 90o.
Refraction Slide:
13. 5
REMEMBER
Critical angle means the angle of refraction is 90o.
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11. The
End
… and good luck!