PHY 21 — Fall 2024

Teaching Assistants

Required Materials and General Information

If you did not opt into Learning Unlimited or if you would like to have a paper textbook, instructions about the textbook follow.

Textbook

The textbook used in this course is Randall D. Knight, Physics for Scientists and Engineers: A Strategic Approach. The current edition is the 5th edition, and there are various ways to get it (Learning Unlimited is an option, the bookstore is another one). Note however that you are also required to sign up for Mastering Physics (see below), and sometimes you can get the cheaper on-line version of the textbook when signing up, some other times you can get a code for signing up when you purchase a new textbook (ask the bookstore for details). Check what the current options are.

In any case, be aware that there are ways to save money on paper textbooks: One possible way is to get an older, used version of the textbook. The order of the chapters may be different, but the contents are the same. In the class plan, I will offer pointers to both the current edition (the 5th) and to an old edition (the 3d) of the textbook. This way you can get the used old edition (in paper form!) from several places for ~$20 (check out amazon or ebay, but be carefull to look for the used<\it> books). If you would like to explore the option of getting the older, used book, below are the details for the 3d edition (otherwise check the bookstore, or what they offer you when signing up for Mastering Physics):

Mastering Physics

Official Pearson Enrollment Instructions

Note that Pearsons (the company behind masteringphysics and the textbook) unfortunately may require you to purchase a new access code for MasteringPhysics even if you already have on old one, because they bind access codes to the textbook that each course uses. In any case, the cheapest option if you already got the used 3d edition book is to simply purchase the registration to masteringphysics on-line.

Coursesite

Activities

Lectures

Lectures are held twice a week, on Tuesday and on Thursday. The lectures introduce new materials and discuss the most important facts and techniques. The ability to use these facts and techniques is then developed via individual work on various types of problems (weekly homework assignments), and exercised and discussed again in recitation. Facts and techniques are also summarized in the detailed lecture summaries that will be made available on coursesite. In addition, you should read additional explanations on the textbook. The lectures are important because they serves as a guide to navigate the material and because they highlight the most important facts. But reading and re-reading all the written materials is necessary, and the combined activities of working on the homework assignments, noticing the things that you don't understand, and then asking questions are ESSENTIAL.

Materials

Class materials and current announcements are published on coursesite. These will be a PDF of the weekly "learning homework", PDFs of lecture Summaries, homework solutions, and additional handouts such as lecture plans, and more.

Quizzes: once a week

Mastering Physics Homework: twice a week

These are the weekly on-line homework assignments (named "MPa" and "MPb") that you can use to exercise the concepts and techniques learned in class and through reading assignments. You must look at each weekly homework assignemnt BEFORE going to recitation, print them all out on either paper or PDF. Then you work on them on paper in your notebook, and then you submit your numerical results into the on-line forms in your masteringphysics account. You do this twice a week, and go over any difficulties during discussions at your recitation meetings.

As a rule, TWO new homework assignments become available every week. One assignment becomes available on Tuesdays, to be completed two days later by the midnight of Thursdays; the other assignment becomes available on Thursdays, to be completed by the Tuesday of following week. Because of the difference in turnaround time you will be more likely to find longer problems or more problems in the homework set that is due on Tuesday, but you can collect the homework points that count towards the final grade from both sets of homework assignments, every week.

IMPORTANT NOTE: THE aim of this online system is (1) to provide you with a bunch of different homework for you to use to test your understanding and for independent study and (2) to allow you to collect "points" that count towards the final grade (see syllabus). Because of the need to also do (1), and not only (2), there will be generally more problems available than what would strictly need to only collect enough homework points. Use all the problems by looking at them and testing if you understand what they are asking, do this even before thinking about finding a solution. Then also use the same problems later, when studying. You do NOT need to do every single problem by the deadline. you can pick and choose which one you will do. Try to do enough of them wo that you collect an average of about 12 points each week (or more). You get points when you provide correct answers, but the system allows you to ask for hints, and there is no deduction if you do problems and enter incorrect answers.

Learning Homework: one problem, once a week

The Learning Homework (LHW) is a longer form homework assignment done on paper and handed in to your TA in recitation. The LHW is designed to promote communication and discussions (between students and between students and instructors) and it will help towards a deeper understanding of a technique or a topic. It is made available as a PDF file on coursesite each Tuesday.

A warning to manage expectations: The LHW are made available also to provide some challenge to students who are more interested in the topic. While they also provide "homework points" that count towards the final grade (see syllabus), sometimes you may decide to only do a portion of them and not go to the end of every question. This is perfectly fine! But in any case you can use the LHW by studying the LHW solutions that appear on coursesite each week. This way you get additional information on important physical principles and you see examples of how to apply the concepts and techniques that must be learned in this course.

Also to promote discussions, the LHW must be done in two steps. First, on the next Friday recitation after the new LHW was published, you must hand in a narrative. This is an English text that describes with complete sentences how you plan to solve the problem (this is the part where you think about the ideas and general concepts). Second, on the Friday one week later, you hand in your final solution (this is the part where you develop those ideas and concepts using mathematical tools).

The narrative does not need to be a very long essay: you should just write down what you think are the main ideas behind the homework and the steps that you plan to follow to reach a solution, or any other comments or guesses. You an also add questions for your TA.

Important: The greatest difficulty in solving problems in physics, in particular at the beginning, is not in the math that we use, it is in knowing how to set up a plan to reach a solution, it is in knowning what intermediate steps one needs to take to arrive at a certain conclusion, or which equations correspond to these steps. For the Learning Homework Assignments, we make this development of the route towards a solution an explicit requirement, in the form of the narrative that must be handed in a week before the final solution is due. In general, avoid seeking out the help of somebody who would tell you how to solve a problem, leaving only the math for you to do. You need to exercise how to arrive at a plan for solving the problem, not just exercise the math once you are told what to do.