refraction power- point power point 10-3

Refraction Power-PointPower Point 10-3

DefinitionRefraction- the bending of a

wave or particle as it passes from different mediums

ApplicationA fish appears higher than it actually is…

Bending Toward the Normal

When light goes from a less dense to more dense medium, it is bent toward the normal. This is an example of air going to fiberglass.

Bending Away from the NormalWhen light passes from fiberglass to air, it bends

away from the normal.

The index of refraction (n)The speed of a wave is slower in a more

optically dense medium.

A relationship…The relationship between the index of refraction

(n) and the speed of the wave can be determined by

Example 1: What is the speed of light in a diamond (n=2.42)?

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v =cn

where c=3 X 10 8 m/s

Snell’s LawThere is a mathematical relationship between:

n= index of refraction for a materialAngle of incidenceAngle of reflection

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n1 sinθ1 = n2 sinθ2Example 2: What is the angle of refraction of light going at an angle of 10 o from a diamond (n=2.42) to air (n=1.0)?

Total Internal ReflectionOnly occurs when light goes from more dense to

less dense. Three cases:

(1) Refracts- bends away from normal (o-43o)(2) Critical angle- prism(3) Reflection

Example 3: What is the maximum angle of incidence in a diamond where refraction occurs? (the angle of refraction is 90o or the critical angle)

Total Internal Reflection

Applications of RefractionFiber optics, polar bear skin, sparkling of

diamonds

Lab…Semicircular Prisms

Rectangular Prism

Right Triangle Prism

Example 4: Double Refraction

A layer of oil (n=1.45) floats on water (n=1.33). A ray of light has an incident angle with the oil of 40o. What is the angle that the ray travels in water?

Equilateral Triangle PrismSince speed of wave is slowing in glass (n=1.52)Red is longest wavelength (700 nm); lowest

frequency; bends the least.Violet is the highest wavelength (400 nm);

highest frequency; bends the most.

Pink Floyd…Which is correct?

Example 5:Angles in Equilateral Triangle

It is observed experimentally that the angle resulting in a prism is 41.5 o in crown glass (n=1.52). Determine the angles in the diagram provided.