Physics 224 - Exam #4 - Final
Spring 2009
Name______
Total Problems 1 - 6:______/60
Total Problem 7:______/25
Total Problem 8:______/25
Total Points:______/110
Percentage Score:______%
***Answer all problems! Each of the problems requires you to show all the steps in obtaining the answer. This includes, but is not limited to, defining all variables, showing the equations to be used, and including units with all values listed. Problems 1 - 6 are worth up to10 points each. Problems 7 & 8 are worth up to 25 points each. Good Luck!!!!
1) The diagram below represents a ray of monochromatic light (f = 5.09 × 1014 Hz) passing from medium X (n = 1.46) into fused quartz (n = 1.458). Which path will the ray follow in the quartz?
a) Only A
b) Only B
c) Only C
d) Only D
e) More than one of the above is possible
f) None of the above is possible.
2) Consider the light rays depicted in the figure. What type of reflecting or refracting surface is depicted?
1. Concave mirror
2. Concave lens
3. Convex lens
4. Convex mirror
5. Plane mirror
6. Unable to determine.
3) In a Young's double slit experiment, the slit separation is doubled. This results in
1. a halving of the spot spacing.
2. a decrease in spot intensity.
3. a halving of the wavelength.
4. an increase in spot intensity.
5. a doubling of the spot spacing.
6. None of the above is possible.
4) When light passes from air into water, the frequency of the light remains the same. What happens to the speed and the wavelength of the light as it crosses the boundary in going from air into water?
Speed Wavelength
1. Increases Remains the same
2. Remains the same Decrease
3. Remains the same Remains the same
4. Decreases Increases
5. Decreases Decreases
5)
6) A ball sits in the bottom of an otherwise empty tub at the front of the room. Suppose N people sit high enough to see the ball (N = 9).
Suppose I fill the tub with water but the ball doesn’t move.
Will more or less people see the ball?
a) More people will see the ball
b) Same # will see the ball
c) Less people will see the ball
7) Two plane mirrors are inclined at an angle f to each other as indicated in the figure. An incident ray is reflected from each of the mirrors as shown. What is the relationship between the three angles f, q, and b? I.e. determine a single equation that contains ONLY the three angles f, q, and b; thereby showing the relationship between them! Both "dashed" lines shown are the normals.
8) Light strikes a water (n = 1.33) surface from the air (n = 1.00) at an incident angle of 45o (qi). The part of the beam refracted into the water strikes a submerged glass slab (n = 1.50), as illustrated in the figure below (NOT shown to scale). The top of the glass slab is observed to make a 20o angle with the water's surface (q). Given this information, determine the angle of the refracted beam inside of the glass slab.