Physics 123A Waves

1
Physics 123A Waves Modern Physics
Review 2TM Chapters 31.1-3, 32, and 33
November 9, 2009 (21 Slides)

• John G. Cramer
• Professor of Physics
• B451 PAB
• cramer_at_phys.washington.edu

2
Review 2 Announcements

• Wednesday is the Veterans Day Holiday, so do
  not come to class then. Lecture Homework 6 is
  not due until November 20.
• We will have Exam 2 on Friday, November 13.
  There will be assigned seating. If you want a
  left-handed aisle seat, a right-handed aisle
  seat, or a seat near the front, of if you require
  one of the four table seats in the back, send me
  E-mail with your request.
• So far 181/196 students have registered their
  clickers, so there are still 15 holdouts. A
  clicker response that shows up as a number may
  indicate a registration problem.

3
Lecture Schedule (Part 2)
We are here!
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About Exam 2

• On Friday, November 13 we will have Exam 2, which
  covers TM, Chapters 31.1-3, 32 and 33 and my
  lectures 9-15.
• Exam 2 will have assigned seating. Check
  WebAssign for your seat assignment.
• Exam 2 is closed-book, but you may bring with you
  one page of notes on a 8½x11 sheet of paper
  (both sides).
• Bring a Scantron sheet, a straightedge or ruler,
  and a scientific calculator with good batteries.
  
• Exam 2 will have a multiple-choice section (55
  pts) of questions similar to homework problems,
  lecture example problems and the two-dot
  end-of-chapter problems in TM.
• Exam 2 will have a Laboratory free-response
  section (25 pts).
• Exam 2 will have a free-response section (20 pts)
  based material from the Tutorials.

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Chapter 31
6
Example Total Internal Reflection
A light bulb is set in the bottom of a 3.0 m
deep swimming pool. What is the diameter of
the ring of light seen on the pools surface?
This is the so-called ring of bright water
seen when looking up from within a pool of water.
The outside world is compressed to lie within
the ring.
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Chapter 32-1
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Chapter 32-2
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Chapter 32-3
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Chapter 32-4
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Chapter 32-5
12
ExampleMagnifying a flower
To better view a flower, a naturalist holds
a 6.0-cm-focal-length magnifying glass 4.0 cm
from the flower. What is the magnification?
13
ExampleDemagnifying a flower
A diverging lens with a 50-cm-focal-length
is placed 100 cm from the flower. Where is
the image? What is the magnification?
14
ExampleA Compound Microscope
A microscope has an f1 1.2 cm objective
lens and an f2 2.0 cm eyepiece, with the lenses
separated by 20.0 cm.(a) Find the magnifying
power if the near point of the viewer is 25.0
cm? (b) Where should the object be placed if the
image is to be viewed at infinity?
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Chapter 33-1
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Chapter 33-2
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Chapter 33-3
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Example Fringe Spacingfrom Slit Spacing
Two narrow slits separated by d 1.50 mm
are illuminated by yellow light from a sodium
lamp that has a wavelength l 589 nm. Find
the spacing of the bright fringes observed on a
screen located L 3.00 m away.
19
Example Diffraction of a laser through a slit
Light from a helium-neon laser (l 633 nm)
passes through a narrow slit and is seen on a
screen 2.0 m behind the slit. The first minimum
of the diffraction pattern is observed to be
located 1.2 cm from the central maximum. How
wide is the slit?
20
Example Measuring Wavelengths Emitted by Sodium
Light from a sodium lamp passes through a
diffraction grating having 1000 slits per
millimeter. The interference pattern is viewed
on a screen 1.000 m behind the grating. Two
bright yellow fringes are visible at distances of
72.88 cm and 73.00 cm from the central maximum.
Assuming that m1, what are the wavelengths of
these two fringes?
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End of Review 2

• So far 182/196 students have registered their
  HiTT Clickers. You should register your clicker
  (using the link on the 123A Syllabus page) as
  soon as possible, no later than the last lecture.
• Lecture Homework 6 is due at 1159 PM on
  Friday, November 20.
• We will have Exam 2 in this room on Friday,
  November 13. It will consists of a 55 point
  multiple-choice part, a 25 point Lab
  free-response part, and a 20 point free-response
  based on the tutorial. You may bring one sheet
  of notes (both sides). You should bring a
  Scantron sheet, a straightedge, and a calculator
  with good batteries.