Physics 202 Homework, Day 22: Chapter 22: #34, 37; Chapter 23: #3,6,7,9
ü 34. For light of wavelength 589 nm [the value used in the index of refraction table], calculate the critical
angles for the following substances when surrounded by air:
(a) fused quartz [n = 1.458]
(b) polystyrene [n = 1.49]
(c) sodium chloride [n = 1.544]
In[159]:=
nQuartz = 1.458;
Print@"Critical
Print@"Critical
Print@"Critical
nPolystyrene = 1.49; nSodiumChloride = 1.544;
Angle for quartz = ", ArcSin@1 ê nQuartzD ê Degree, " °"D
Angle for polystyrene = ", ArcSin@1 ê nPolystyreneD ê Degree, " °"D
Angle for sodium chloride = ", ArcSin@1 ê nSodiumChlorideD ê Degree, " °"D
Critical Angle for quartz = 43.3041 °
Critical Angle for polystyrene = 42.1552 °
Critical Angle for sodium chloride = 40.366 °
ü 37. A plastic light pipe has an index of refraction of 1.53. For total internal reflection, what is the minimum
angle of incidence (from the plastic travelling toward the outside) if the pipe is in (a) air, and (b) water
nPlastic = 1.53; nAir = 1.000; nWater = 1.333;
Print@"Critical Angle for pipe surrounded by air = ", ArcSin@nAir ê nPlasticD ê Degree, " °"D
Print@"Critical Angle for pipe surrounded by water = ",
ArcSin@nWater ê nPlasticD ê Degree, " °"D
Critical Angle for pipe surrounded by air = 40.8132 °
Critical Angle for pipe surrounded by water = 60.6033 °
ü 3. A person walks into a room that has, on opposited walls, two plane mirrors producing multiple images.
Find the distances from the person to the first three images seen in the left-hand mirror when the person is
5.00 ft from the mirror on the left wall and 10.0 ft from the mirror on the right wall.
The first image is 5 feet behind the left hand mirror, or 10 feet from the person.
The second image is a reflection of the image formed in the right-hand mirror. the image in the right hand mirror is 10 feet
behind the right hand mirror which is 15+10 = 25 feet from the left hand mirror. That makes it 5+25 = 30 feet from the
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r
s
o
n
.
Therefore the second image is 25 feet behind the left-had mirror. The third image is the reflection from the reflection, so it is
5+15+15 = 35 feet behind the left-hand mirror, or 40 feet from the person.
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Day_22_sol.nb
ü 6. A dentist uses a mirror to examine a tooth that is 1.00 cm in front of the mirror. The image of the tooth is
formed 10.0 cm behind the mirror. Determine (a) the mirror's radius of curvature and (b) the magnification
of the image.
ü 7. An object is placed 40.0 cm from a concave mirror of radius 20.0 cm. (a) Find the location of the image.
(b) What is the magnification of the mirror? Is the image real or virtual? Is the image upright or inverted?
Day_22_sol.nb
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ü 9. An object of height 2.0 cm is placed 30 cm in from a convex mirror of a focal length with magnitude 10.0
cm.
(a) Find the location of the image.
(b) Describe the properties of the image.