PHYS 325 :: Physics Illinois :: University of Illinois Urbana-Champaign

Course Description

General overview

You should go to the section you are registered in, as space is limited. Attendance in lectures and discussion sessions is part of your grade. Please review the section information for lecture and discussion times this semester.

PHYS 325 is the first half of a 2-semester sequence on Classical Mechanics, with PHYS 326 being the second half. You will learn about Newtonian kinematics and dynamics, including gravitation, in three dimensions, conservation laws, damped and periodically driven oscillations, motion in rotating reference frames, and Lagrangian and Hamiltonian mechanics.
PHYS 325 will probably require more work than your previous physics courses and is a serious departure from "the plug-n-chug from the formula sheet" modus operandi to which you may have become accustomed. You will be deriving analytic expressions, and learning to critique, interpret and apply them.
I expect you to know first year calculus thoroughly and to be prepared to go beyond that level. Topics such as matrices, vector mathematics, multivariable calculus, and differential equations covered in PHYS 225 will be assumed. Concurrent registration or completion of Math 285 or equivalent is also expected. If you plan on taking Physics 326, I strongly encourage you to take a linear algebra class (e.g. Math 415) this semester. Here are links to a couple of collections of math and physics formulae that you may find useful during this course, some of which you may recognize.


Classical mechanics is an old subject and there exist many excellent textbooks.
In this course we will primarily use "Classical Mechanics" by John R. Taylor. This and additional (optional) references for further reading, and links to extra material are listed under Textbooks and extra material.


Lectures take place on Tuesdays and Thursdays, 13:00-14:20 Central US, in 151 Loomis. Lecture attendance will contribute up to 50 points to your grade. We will take lecture attendance via gradescope. The entry code is RK3W2X.

During the lecture you are strongly advised to take your own notes. I am posting lecture notes from the previous semester before the lectures so that you can familiarize yourself with the material.

Discussion sessions

When registering for this course, you registered for a discussion session, which will take place weekly on Mondays. Because space is limited, please go to the section for which you are registered. Please review the section information for discussion sessions scheduled this semester.

You will be able to access the material for the discussion session online.

Discussions are graded on attendance and will make up 12% of your grade. That said, your TA may reduce attendance points if you do something else. In particular, if you have questions about the homework, do so in the Office hours. Late policy: if you are more than 10 minutes late, your score will be reduced by 20%. Being more than 30 minutes late counts as absence.


Homework is an essential part of this course and accounts for 33% of your grade.
Homework sets will become available online on Thursdays after class, and will usually cover the lecture material of concurrent week. Solutions will be due one week later, on the following Thursday at 11:55pm Central US. You should upload your completed homework to gradescope. The entry code for the homework is 2PJV8Y.

Unless a valid, verifiable excuse is given, homework sets which are submitted late will receive a 20% penalty. Homework sets which are turned in more than a week late will receive no credit.

I do not object to people working on the homework problems together as long as the work that you hand in for grading is your own. Specifically, do not hand in work that is obviously copied. All work must be your own, with your own reasoning and working. Partial credit will be awarded on homework and exams, so please write out your problems neatly showing all steps and writing IN WORDS what you are doing and your reasoning. This will allow the graders to assign partial credit, and point out where you have made errors. I strongly recommend that you thoroughly struggle with the problems yourself first before you seek out help. You will learn more this way and you will do better on the exams when you are on your own. Trust me on this one.

In general, you are allowed (in fact, encouraged!) to use computer software such as python, Mathematica, Maple, or Matlab to complete your homework problems. If you do use computer algebra software, you must provide a well-formatted print of your code and attach it as part of your PDF solution.
You will not have this capability on the final exam, so I suggest that you use these resources wisely and do not rely on them to do simple algebra, or solve simple differential equations.


There will be two midterm exams, taking place in class in our usual lecture location, worth 15 % each, and one final exam worth 20%.

Dates will be announced. Please check the course schedule and exam page for full details.

The exams are individual exams, i.e., do not provide or receive help from anyone for the completion of the exam.
You are not allowed to use calculators or computers during the exam.
You are allowed one Letter-sized (8.5"x11") or A4-sized (21cm x29.7cm) sheet of paper with hand-written notes. They must be your own work. For the two midterm exams, you may use only one side. For the final you may use both sides. Formula sheets will be provided and will be posted in advance of the exam.
No homework will be due the week of the exam.

Excused Absences

Please submit your excused absence no later than 10 working days from your absence via the Excused Absences application. The count begins the day of your absence.

Academic integrity

All activities in this course are subject to the Academic Integrity rules as described in Article 1, Part 4, Academic Integrity, of the Student Code.

In particular, the giving of assistance to or receiving of unauthorized assistance from another person, or the use of unauthorized materials during University Examinations can be grounds for disciplinary action, up to and including expulsion from the University. Course grading will proceed in compliance with University policy.

Please be aware that prior to or during an examination the instructional staff may wish to rearrange the student seating. Such action does not mean that anyone is suspected of inappropriate behavior.