DO NOW
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DO NOW • What is the color of a light wave with a frequency of 5.65 x 10 14 Hz?
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DO NOW. What is the color of a light wave with a frequency of 5.65 x 10 14 Hz? . Refraction of Light . Refraction . Refraction is the bending of a wave when it enters a medium where it's speed is different. Snell’s Law. The slower the speed, the smaller the angle . Sinθ 1. v 1. =. - PowerPoint PPT Presentation
Transcript of DO NOW
DO NOW
• What is the color of a light wave with a frequency of 5.65 x 1014 Hz?
Refraction of Light
Refraction
• Refraction is the bending of a wave when it enters a medium where it's speed is different.
Snell’s Law
• The slower the speed, the smaller the angle
Sinθ1
Sinθ2
v1
v2
=
Snell’s Law
Snell’s Law
• Monochromatic light passes between two media. If the angle in medium 1 is 45° and the angle in medium 2 is 30°, calculate the ratio of the light speeds between media 1 and 2.
V1 = 1.4v2
Absolute Index of Refraction
• Always greater than or equal to zero• The larger n, the slower the speed of light in a
medium
Absolute Index of Refraction
• The speed of light in a medium is 2.4 x 108 m/s. What is the absolute index of refraction of the medium?
1.25
Snell’s Law
n1sinθ1 = n2sinθ2
n2
n1
v1
v2
=
Snell’s Law
• A monochromatic light ray is incident on a surface boundary between air and corn oil at an angle of 60° to the normal. Calculate the refracted angle of the ray in the corn oil.
n1sinθ1 = n2sinθ2 θ2= 36°
Critical Angle
Critical Angle
• Calculate the critical angle between diamond and Lucite.
θc= sin-1 (n2/n1)
θc = 38°
Total Internal Reflection
• If the critical angle is exceeded, the light can no longer escape but will be reflected back into the medium.
Total Internal Reflection
Total Internal Reflection
• the light is in the more dense medium and approaching the less dense medium.
• the angle of incidence is greater than the critical angle.
Dispersion
Speed of light in the prism depends on the color of the light (frequency)
Practice!
Page 493: Practice A- 1 & 3Page 493: Section Review – 1 – 4 Page 508: Practice C- 1 & 2 Page 511: Section Review- 1 & 3
• Draw a diagram of a ray of light traveling from an unknown medium into glycerol. If the angle of incidence is 40 degrees and the angle of refraction is 46.5 degrees, what is the index of refraction of the unknown medium? Is it more or less dense than glycerol?
EXIT QUIZ
A ray of light travels from water into air with an incident angle of 23 degrees. What is the angle of refraction?
