PHY138Y |
Waves
Assignment 4 |
Prof. Jason Harlow |
Physics Department |
Due |
|
Please complete the following problems on separate
paper. Show all your work legibly, and
draw a box around the final numerical answer where applicable. Use one staple in the upper left-hand corner
to connect multiple pages, and slip the entire assignment in the drop-box for
your Tutorial Section at the bottom of the stairs of
Supplemental Problem:
In the sketch above, a light
ray, shown by the black jagged line, travels from material A, through three
layers of other transparent materials, then back into another layer of material
A. The surfaces between the materials
are all parallel to one another. The
refractions (but not the associated reflections) at the surfaces are shown. Rank the materials according to their indices
of refraction, greatest first.
From the Textbook:
25.11, 25.30, 26.3
Some suggested problems from the Textbook (not to be
turned in):
Questions 2, 4 and 12 on
page 957
Problems 25.3, 25.7, 25.27,
25.31
Questions 10 and 22 on page
994
Problems 26.23, 26.27,
26.33, 26.39
Some PHY138Y Laboratories that relate somewhat to this
material:
Refraction of Light
(non-core)
Spectra (core)
Optical Fibres
(non-core)
Suggested Supplemental Problem (not to be turned in):
The human eye has a diameter
of 3 cm. It can be modeled as a lens of
focal length f2
, 3 cm in front of a retina, onto which an image is projected. If the image of the object is projected
exactly onto the retina, a crisp image is seen.
If the image of the object is projected in front of or behind the
retina, the light that falls on the retina will not be in focus, and a blurred
image will be seen.
Part 1:
The far-sighted eye. Consider a person with a lens with focal length f2=2.94 cm, who is trying to
focus on an object that is 21 cm in front of the lens of her eye. Find the location of the image. Is it exactly 3 cm beyond the lens, and
therefore on the retina?
Part 2: A
converging corrective lens. Now consider
the situation depicted in the diagram below.
A converging lens of focal length f1=23.2
cm is placed 20 cm to the right of an object.
1 cm to the right of this first lens is the lens of an eye, with f2=2.94 cm.
a) Where is the image formed by the first lens? Is it real
or virtual?
b) Following the procedure described in the final
paragraphs of Section 25.4 in Serway and Jewett, make
the image of the first lens the object of the second lens. How far in front of the second lens is this
object?
c) Compute the location of the final image formed by the
second lens. Is it exactly 3 cm beyond
the lens, and therefore on the retina?