PHYSICS 141 - 09

Winter Quarter 2009

Instructor: Dr. Ronald F. Brown

Office: Science Bldg. 52-D1 email: rbrown@calpoly.edu

http://www.calpoly.edu/~rbrown

Office Hours:    Mon. 1-2;, Tues. 3-4; Wed. 3-4; Thurs. 1-2

Texts: Young/Freedman, UNIVERSITY PHYSICS, 12th ed., (Addison-Wesley 2008)

Brown, Physics 141 SUPPLEMENTAL NOTES AND PROBLEMS, El Corral

References: Any other calculus-based introductory physics text.

Physics 141 is an introductory calculus-based course in classical mechanics. Topics include the description of motion, Newton's laws, the concepts of force, work and energy, impulse and momentum, and torque and angular momentum and the three conservation laws (energy, momentum, and angular momentum) that characterize the motions of objects and the principles that govern their motion.

COURSE FORMAT

CLASS MEETINGS - Each class meeting will include some lecture and some discussion. You are expected to read both the text and Supplemental Notes, work through examples, and do problems prior to each class meeting. The discussions can then deal with any material that is difficult to understand, approaches to problem solving, explanations of concepts, and insights into the significance of the ideas of physics. How profitable the class meetings are depend very much on your level of preparation and participation. You are expected to attend and participate in all class discussions.

STUDY GROUPS - You are encouraged to get together in study groups to discuss the material, sort out difficulties, and work on homework. Trying to help a fellow student through the material can be very effective in your own study - it helps solidify what you do know and expose those areas where the ideas are not yet secure. Make good use of your study group to stay on top of the material (and simply lead to some interesting discussions). But be careful not to rely entirely on the group. Learning is ultimately an individual effort. Be sure to do independent thinking and study as well as group work.

HOMEWORK - Learning is not a passive experience. Homework will be assigned regularly. The purpose of the homework, of course, is to help you understand the material - it is not an end in itself, nor is it a substitute for reading the text and Supplement and your study of the ideas and concepts. Homework is most effective if it is being worked on while the material is being discussed in class (rather than after the material has been completed in class). Many (maybe even most) of the problems that will be collected will be based on problems in the Supplemental Notes. If you have difficulty with those problems, ask about them - in class, in study sessions with your classmates, and in office hours or by email. In many cases, there will be similar problems in the textbook

NOTEBOOK - You should maintain a Physics 141 notebook. In your notebook, you should keep notes from class and from your study of the material, the textbook problems you do for practice including explanations of the approach used, etc. – all of that should be done in your notebook so that you keep it all together. Bring your notebook with you when you come to office hours so I can see your approach to your work. You are always welcome to ask about problems - both those assigned and unassigned. I may ask to see your notebook at the end of the quarter – esp. if you are not doing well. If you maintain such a notebook, studying for tests and the final should be easy since it means reviewing your notes and approaches to problems rather than redoing all of your work.

QUIZZES - There will be occasional announced quizzes given in class. There may also be some take home problems that let you test yourself. If there are take-home self-check quizzes which do not count - you should still do them as if they counted and evaluate them carefully to see if you are adequately prepared at that point in the quarter.

EXAMS - There will probably be two mid-term exams in addition to any quizzes and a comprehensive final exam. The exams will include both problems to set up and/or solve and conceptual questions on the material. Your exam scores will be based on both the correctness of your work and the clarity of your approach. The exams are usually non-numerical (hence do not require a calculator) – or, if numerical, answers can be estimated (and the grading is based on the set up and solution to the problem, not the answer). Please contact me if you have difficulty with examinations as a method for testing your understanding of the material.

FINAL EXAM - The final exam will be comprehensive and will stress the concepts of physics and applications of the concepts to problem solving.

FINAL EXAM: Friday, March 20, 1 – 4 pm

If, for some good reason, you must miss an exam, arrangements must be made before the exam is given. If a test-day emergency or illness prevents you from taking a quiz or exam, contact me that day and make arrangements with me as soon as possible if a make-up is in order.

GRADING

Grading in the course will be based primarily on the quizzes, the mid-term exams, and the final - but your involvement and participation in the course will also be a component of the final grade. Homework will only count in a marginal way toward your grade, but the problems that you submit do indicate your level of engagement in the course and could affect your grade.

The grade you receive ultimately should reflect what you know and are able to show of your knowledge of the material of this course and in setting up and solving problems. Testing is just an attempt to measure that knowledge and ability. If this class is typical, a majority of the grades will be in the A-C range. But you will receive a grade of C– or better only if you have taken all quizzes and tests, and then are able to show on the final exam that you have a sufficient mastery of the material of this course to move on to a subsequent course that depends on this material. A grade of D or F simply means that, in my judgment, this course needs to be repeated before proceeding to another course that depends on this material. What you get from this class is very much up to you and the effort you put in. But realize that a lack of preparation early in the quarter will make it very difficult to gain a solid understanding of the material later in the course.

You are responsible for your own education.

Learning to think and work independently is an integral part of that educational process.  The work you submit must be your own unless cooperation is explicitly allowed.  The principle is simple:  You are responsible for your own work - and you are responsible for your actions.

You have an absolute right to expect me to be honest with you.  I expect no less of you.

You also have a responsibility to the class. That is, to make the class more effective, be on-time, be attentive, turn off your cell phone, don’t leave class unless it is an emergency. Interruptions can be distracting – for you, for your fellow students, for the instructor.

COURSE OBJECTIVES AND TOPICS

An active participation in this introductory course in physics should yield:

1. An understanding of the basic laws of nature which affect the way objects move.

2. An ability to set up and solve basic problems by applying the principles of physics which deal with forces, stability, motion, energy, momentum, angular momentum and the conservation laws.

3. An ability to state and use such principles as Newton’s laws, the conservation of energy and of momentum, etc. , in explaining the motions of many different objects and systems of objects.

4. The ability to describe how objects behave in a variety of ways - in words, graphically, and mathematically – and to make judgements about their motions based on those descriptions.

The goals of this course include establishing the underlying logic associated with the principles of physics - in particular regarding the motions of objects. You should be able to make the connections between observations that we make and the principles that describe them - ie, relate theory and experiment. It should be clear that what we claim to know is ultimately based on observations. That the ideas of physics are testable should become clear from the discussions in the course. Finally, the course should help you develop problem solving skills - rather than just present a set of standard problem solutions to be learned. Simply knowing problem solutions is of little importance. But knowing how to make decisions based on principles - as a method of problem solving - is a primary goal of this course.

DESCRIPTION OF MOTION

Average and instantaneous velocity and acceleration; The kinematics equations; Freefall problems.

Velocity and acceleration as vector quantities; Projectile motion; Uniform circular motion

FORCES, NEWTON’S LAWS AND APPLICATIONS

The nature of forces as interactions. Newton’s three laws: Inertia, Motion, Interaction

Gravitational force; Relationship between mass and weight; Using Newton’s laws - Force diagrams Contact forces and friction; Dynamics of circular motion

WORK, ENERGY, AND MOMENTUM - THE CONSERVATION LAWS

Definition of work; Kinetic energy; The Work-Energy theorem; Power;

Potential energy and conservative forces; Gravitational and elastic potential energy

Non-conservative forces; Conservation of energy; Using energy conservation in problem solving

Systems of particles; Momentum; Conservation of momentum; Collision problems

ROTATIONAL MOTION; TORQUE AND ANGULAR MOMENTUM

Angular velocity and acceleration; Torque and angular acceleration;

Kinetic energy of rotation; Moment of inertia; Rotation about a moving axis

Angular momentum and angular momentum conservation

Finally, it is important that you approach the study of physics systematically. The study of physics requires assimilating and using the information gained from your reading, the laboratory, lectures and discussions, and your work on solving problems.