It is the most persistent and greatest adventure in human history, this search to understand the universe, how it works and where it came from. It is difficult to imagine that a handful of residents of a small planet circling an insignificant star in a small galaxy have as their aim a complete understanding of the entire universe, a small speck of creation truly believing it is capable of comprehending the whole.
- Murray Gell-Mann, Caltech physicist
The second course in the General Physics sequence. This course extends the ideas of Newton's laws and energy concepts to oscillations and waves, including sound; to heat and temperature, the thermal properties of materials and the principles of thermodynamics; and to light, geometrical optics, and interference and diffraction. (It is almost like three short courses, rather than the continuous thread of related topics that was encountered in Phys 141.)
If the first course in the sequence dealt with the motion of objects - either single particles or collections of particles that can be treated as single objects (like balls or blocks), this course can be thought of as dealing with the collective motion of systems of particles. Liquids and gases are interacting systems of huge numbers of particles - but can be understood as systems without knowing how individual particles behave. Wave motion is a further extension of the ideas with the description of the motion of "disturbances" being the interest. All thermodynamic processes are ultimately related to the microscopic motions of the atoms that make up the objects or systems being described. And finally, the ideas of wave motion will be applied to light - with analogies to the discussion of sound being made where appropriate.
Last updated: September 15, 2009
Instructor: Dr. Ron Brown - Physics
Department Office: Science Bldg 52 - D1
Office Hours: M
2-3; W 2-3; Th 2-3; Fri 2-3
Telephone:
756-2448
Email: rbrown@calpoly.edu
Textbook: UNIVERSITY
PHYSICS by Young and Freedman, 12th edition
Reference: Brown, Physics 132 SUPPLEMENTAL NOTES AND PROBLEMS, El Corral
Textbook: Young & Freedman, UNIVERSITY PHYSICS - 12th edition
References: Physics 132 - SUPPLEMENTAL NOTES
AND PROBLEMS
, El Corral (Fall 2008)
Office
Hours - Don't wait until you are
in trouble in the class.
When you don't understand or want something clarified, ask! If you
cannot get
to office hours for some reason, contact your instructor after class or
by
email to set up a time to meet - or just stop by the office.
Physics Learning Center - The Learning Center will be open starting the second week of classes. - Faculty and student tutors from Physics department hold office hours in the Learning Center - Sci. Bldg. A-03 (a converted lab). It is a good place to go to work HW (with help immediately available) or to ask questions of whoever is "on call".
Learning
Center Hours: To be arranged - but typically mid-morning to
mid-afternoon
Physics
132 - Supplemental Notes and
Problems This supplemental set
of notes
(about 100 pages) summarizes the important concepts of this course. The
notes
treat the material differently than the text - the focus is on the
concepts,
the underlying ideas, rather than on how to apply the ideas to
problems. You
should look at the Supplement and decide whether it would be helpful
for you.
Included are questions and problems to test your thinking. The
current version of Physics 132 -
Supplemental
Notes and Problems is available at El Corral with the other
physics books. Scroll down to the NOTES section for links to pdfs of
the first two chapters.
Private
Tutoring - Individual
arrangements can be made with Physics
majors available for tutoring in Sci. Bldg. room E-25 (known
affectionately as
"h-bar" - a physics in-joke)
Drop-In
Help - Those same tutors will
also help for free if you
just stop by "h-bar" and ask questions
Posted Solutions and Hints - Selected problem hints and/or solutions will be posted on the bulletin boards just outside the Phys 132 laboratory (E-33) and occasionally on the board near E-47
Look here for information about this section.
Week No. 1: Simple Harmonic Motion
· Take Home Diagnostic Pre-test - Due in class on Thursday.
·
Following a brief introduction to the
course – we will
begin the discussion of simple harmonic motion.
What are the essential ideas that determine why and
how things oscillate. The
mathematics of harmonic motion requires combining Hooke’s law (for
springs) and
Newton’s second law of motion to obtain the equations that describe
simple
harmonic motion. Those ideas will
be a central part of our discussion for the first three weeks or so.
•
Experiment: Pendulum motion
Week No. 2
Energy of Oscillation
Problem Set No. 1 - Due the following Tuesday
·
We
will continue the discussion of simple harmonic motion on Tuesday -
including
the energy of oscillation. We will also introduce the effect of damping
on
harmonic motion - and describe how the amplitude of oscillation
diminishes as a
result of damping forces. On Thursday, the idea of resonance will be
introduced, without trying to deal with the mathematical details.
Experiment: Mass-Spring systems
Week No. 3: Wave Motion - Traveling Waves and Standing Waves
· Problem Set No. 2 - Due Tuesday - Problem Set No. 3 - Due Friday
· We will extend the discussion of traveling waves on strings to examine how standing waves can be created when a wave is reflected back on itself. This is an example of standing wave resonance - and is the subject of this week's laboratory. The material is found in Ch. 21.
·
By Friday, we will begin the discussion of
sound - and show that the
description of sound waves is nearly identical to that of waves on
strings. The HW problems that will
be due on Friday will be on standing waves on strings.
·
This
week's lab experiment deals with standing wave resonance on stretched
strings. You will use the standing wave resonances to
experimentally
verify that the wave speed on a stretched string depends on the tension
and the linear mass density.
This important chapter is the basis for
understanding many natural
phenomena involving oscillatory behavior - from atoms in crystals to
Cepheid variable
stars. The ideas follow directly from Newton's laws and must be
understood well
in order to understand the descriptions of mechanical wave motion - the
material that follows in the next chapter. Harmonic motion is
ultimately a
consequence of the natural tendancy of things to seek their lowest
potential
energy, "overshoot", and then oscillate around their equilibrium
positions. The discussion will lead to the idea of resonance - a
phenonomenon
which occurs throughout nature.
The discussion of wave motion in the text in an integrated approach to waves - and deals with transverse and longitudinal traveling waves of various types including waves on strings, sound waves and light in the same discussion. The interference of waves (of all three types) to create standing waves will appear in Ch. 21. The Supplemental Notes treats waves on strings - both traveling waves and standing waves first, then deals with sound both in traveling and standing waves, interference, and Doppler effect.
The purpose of the HW assigned is to give you some practice with the manipulations and to invite you to explore some results you might not have thought about before. The answers are not nearly as important as developing a systematic approach to such problems. There are a lot of problems - do enough of each type that you are sure that you are not missing some skill you will need. You should READ more problems than you DO, just to see what kinds of things you have the ability to figure out.
Maintain a HW notebook. Do all of your problems (including writing out answers to the conceptual questions) in your notebook. State how you are doing each problem - ie, explain the lines of reasoning for each problem. That will be invaluable when you are studying for a quiz or exam - reviewing your explanations of the principles and approaches used in solving the problems will be a good way to prepare for tests.
Selected HW problem solutions are posted outside the Phys 132 laboratory (E-33).
The HW hints and solutions are also linked to the Physics Dept. PHYS 132 Homepage: Homework Hints and Solutions
Use the HW problems well. The point is not to just finish the assigned problems, but to learn from them. You may not need to do all the problems to develop the skill and confidence needed for the next chapter - or you may need more than just those assigned. There are undoubtedly additional problems that would be good choices to work on. But do not just skip over problems you think you can do without actually carrying out the work. Ultimately, you will need to demonstrate that you can do the steps and interpret the results. You know that you understand the problems when you can explain them to someone else. Study groups help that process.
Look here each week for a brief description of the laboratory experiment.
Week No. 1: Exp. 1 – THE SIMPLE PENDULUM
This week's
experiment deals with the motion of a simple pendulum.
In particular, it deals with the
discovery of the relationship between the period of the pendulum and
its
length. This is a great example of
how simple measurements can reveal the mathematical relationship
between
quantities.
Week No. 2: Exp. 10 - HARMONIC MOTION
This week's experiment deals with a mass-spring system. The purpose is to verify the relationship between the period and the mass. The experiment has two parts: You will first suspend weight from a coiled spring to determine the spring constant (by plotting the force required to stretch the spring vs the extension - then taking the slope of the graph). In the second part of the experiment, you determine the period of the mass-spring system as a function of the mass in order to experimentally verify the equations used in describing simple harmonic motion.
Week No. 3: Exp. 11 - STANDING WAVE RESONANCES ON STRETCHED STRINGS
This
week's experiment has you observe standing wave resonances on a
stretched "shock cord" under tension. The resonances are found by
varying the frequencies of a signal generator that drives the system
and observing the standing waves at specific frequencies.
Graphing the resonant frequencies (ie, the frequencies at which
standing waves are observed) as a function of the wavelength will allow
you to determine the wave speed on the shock cord. You can then
compare the experimentally determined wave speed to the predicted wave
speed based on the tension and mass density.