SNC2D
Unit 4: Optics
The Refraction of Light
Problem Set
The amount that a transparent medium decreases the speed of light is represented by a number
called the index of refraction. The refractive index of the medium is represented by the symbol
n , and is determined by comparing the speed of light in the medium, v , with the speed of light
in a vacuum, c . The mathematical relationship is defined by the formula:
n
c
where c  3.0 108 m s
v
Recall that Snell's Law is a formula that uses values for the index of refraction to calculate the
new angle that ray will take as a beam of light strikes the interface between two media. It is
defined as:
n1 sin 1  n2 sin 2
It can be re-arranged to be expressed in terms of the refracted angle:
 n1 sin 1 

 n2 
 2  sin 1 
Using Snell's Law and the data table below, determine the missing value in each question.
Remember to use problem solving conventions such as listing all of the given information,
required information, solutions showing all of your calculations, and a concluding statement.
Media
air
carbon dioxide gas
water
alcohol
Pyrex glass
Plexiglass
table salt
flint glass
sapphire
cubic zirconia
diamond
gallium phosphide
Index of
Refraction
1.0003
1.0005
1.33
1.36
1.47
1.49
1.51
1.61
1.77
2.16
2.42
3.50
U04A06_Assignment 1
SNC2D
Unit 4: Optics
Questions
1. The speed of light in leaded glass is 1.66 108 . What is the index of refraction of this type
of glass?
2. When light passes from air into water at an angle of 600 from the normal, what is the
angle of refraction?
3. When light passes from water into diamond at an angle of 450 from the normal, what is
the angle of refraction?
4. A ray of light approaches a jar of honey at an angle of 300. If the angle of refraction is
19.50, what is the refractive index of honey?
5. A block of amber is placed in water and a laser beam travels from the water through the
amber. The angle of incidence is 350 while the angle of refraction is 240. What is the
index of refraction of amber?
U04A06_Assignment 1