PH113 Physics III
Test IV
Spring 1998/99
Name _________________________
(Please print in UPPER CASE letters)
_
No books or paper notes are allowed. A one page formula sheet is attached as the last page of this test. It may be
removed and need not be handed in. You may use your laptop and any resources residing on your hard drive. This
includes Maple and Working Model. No network connections are allowed. Any student with a physical
connection between the computer and the network outlet during the test will receive a zero on the test.
Show all your work. No credit will be given for answers appearing without supporting calculations. Partial credit
may be awarded based on clarity and completeness of solution.
1. The diffraction pattern shown below occurs when laser light of wavelength 633 nm passes
through a circular aperture and falls onto a screen located 8.00 m away. Calculate the diameter of
the aperture.
[Picture was like Fig. 37-9 on p. 937 of Halliday, Resnck, & Walker 5/e. Place a centimeter rule
over the pcture and you have the idea.]
.
PH113 Physics III
Test IV
Spring 1998/99
Name _________________________
(Please print in UPPER CASE letters)
2. Light of wavelength 440 nm
passes through a double slit, yielding
a diffraction pattern whose graph of
intensity versus deflection angle 2 is
shown at the right.
(a) Calculate the width of the
individual slits.
(b) Calculate the slit separation.
(c) Verify that the ratio of the intensity of the pattern at 2 = 2.5E to the maximum intensity is
about 3/7 as the graph indicates.
PH113 Physics III
Test IV
Spring 1998/99
Name _________________________
(Please print in UPPER CASE letters)
3. Find the separation of two points on the Moon’s surface that can just be resolved by the 200 in
(= 5.1m) diameter telescope at Mount Palomar, assuming that this separation is determined by
diffraction effects. The distance from the Earth to the Moon is 3.8 x 105 km. Assume a
wavelength of 550 nm.
PH113 Physics III
Test IV
Spring 1998/99
Page 4 of 4
Name _________________________
(Please print in UPPER CASE letters)
4. Rocky the Flying Squirrel sails past points A and B marked on Bullwinkle the Moose’s x-axis
at a speed of V = 0.8 c.
(a)
According to the watch in Rocky’s hand the trip takes 2.00 y. How far does Rocky believe points
A and B are apart?
(b) What is the separation of points A and B in Bullwinkle’s frame?
(c) How long does Bullwinkle think it takes Rocky to make the trip from A to B?
(d) Rocky turns on his flashlight and directs the beam down the x-axis. How fast does the light
appear to travel from Bullwinkle’s point of view?