Snell’s Law Questions
Please show all your work to the following questions.
Reminder n 
sin 1
c
and n1 sin 1  n2 sin  2 or n2 
if n1 = 1 (air or vacuum)
v
sin  2
1.
A beam of light traveling in air strikes a plane glass surface at an angle of
incidence of 52.0 degrees. The refracted ray makes an angle of 31.0 degrees
with the normal to the surface. What is:
a.
the index of refraction of the glass?
b.
the speed of light through the glass in meters/second?
2.
Light, in air, is incident at an angle of 40.0 degrees on the surface of a flint glass
plate (n = 1.71). What is:
a.
the angle of refraction?
b.
the speed of light through the medium in meters/second?
3.
A ray of light traveling through air strikes the surface of carbon disulfide
(n=1.625) at an angle of 50.0 degrees. What is:
a.
the angle of refraction?
b.
the speed of light in carbon disulfide in meters/second?
4.
A scuba diver swimming underwater shines her flashlight out of the water. If the
light strikes the surface of the water at an angle of 38.0 degrees, what will the
angle of refraction be? (n = 1.33).
5.
Light travelling through air encounters a second medium which slows the light to
1.88x108 m/s. What is the index of refraction for the second medium?
6.
What is the index of refraction of a medium when the angle of incidence in air is
30° and the angle of refraction in the medium is 15°?
7.
What is the refractive medium if the angle of incidence coming from air is 50.0°
and the angle of refraction is 35.2°?
Answers
1
a)
b)
n = 1.53
1.96x108 m/s
a)
b)
22.1°
1.75 x108 m/s
a)
b)
28.1°
1.85 x108 m/s
2
3
4
55.0°
5
n = 1.60
6
n = 1.93
7
n = 1.33 therefore the substance is water