Transcript Reflection and Refraction

Chapter 17
Reflection and Refraction
Ch 17.1
How light behaves at a
boundary
I How light behaves at a boundary
A. The law of reflection
B. The refraction of light
C. Snell’s law
D. Index of refraction and the Speed of
light
A. Law of Reflection
Regular reflection
Diffuse reflection
B. Refraction of Light
Bending of light at a boundary
Angle of refraction
Optical density
C. Snell’s law
The ratio of the sine of the angle of
incidence to the sine of the angle of
refraction is a constant.
Index of refraction
n = sin θi /sin θr
Snell’s law
ni sin θi = nr sin θr
PSS
1.
2.
3.
4.
Drawing ray diagrams
Draw a diagram showing the two media.
Label the media and indicate the two
indices of refraction
Draw the incident ray to the point where
it hits the surface, then draw a normal to
the surface at that point.
Use a protractor to measure the angle of
incidence.
5. Use Snell’s law to calculate the angle of
refraction
6. Use a protractor to draw the refracted ray
leaving the surface at the point where the
incident ray entered.
7. Evaluate your work.
Index of Refraction and the
Speed of light
Recall that when a wave moves from one
medium to another where the wave speed
is different, the frequency does not
change.
v = f
material = vmaterial/f
Index of refraction
nsubstance = c/vsubstance
Homework:
– Chapter 17 review problems