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PHYS 123 A: Waves

MWF 2:30pm - 3:20pm / * *
Th 5:00pm - 6:20pm / * *
Shih-Chieh Hsu

Syllabus Description:

Welcome to PHYS 123A. My name is Shih-Chieh Hsu(he/his/ him), and I will be your instructor. 

In this class everyone is welcome, regardless of other identities you hold in addition to that of physics student.  I expect everyone in this class to treat each other with respect.

This is the third of a three-quarter sequence of introductory calculus-based physics.  You should find this course challenging and stimulating, and I hope that you also find it interesting and enjoyable.  Upon successful completion of this course, you will be able to develop calculus-based models to describe the physical world pertaining to the following:

  • simple harmonic motion
  • wave propagation
  • wave interference and diffraction
  • optics
  • heat transfer
  • converting heat to work.


This course has multiple components lecture, lab, and tutorial (QZ section in time schedule) each of which has several important aspects.  These are described below after some general information critical to success in this course.

Resources to Succeed

This website describes recommended practices to succeed in this course, and contains a list of resources you may find helpful for a variety of issues students may encounter during your time at UW.  Contact me if you need help finding the resources you need.

One very important practice described in the above website is working collaboratively.  If at all possible, please do arrange with fellow students to work through assignments together.

Office Hours and Posting Questions

During the week the TAs and I will hold office hours on Zoom where you can ask questions.  Click "Office hours" in the menu on the left for the office hour schedule. 

Use the Discussion Board (click "Discussions" in the menu on the left) for physics questions or syllabus related questions.  Students are encouraged to answer each others' questions, but I will also monitor this frequently and will respond if needed.

Contact information

For questions send an email with your course and section (Phys 123A), your UW netID (the part before in your email address), and name as it appears on Canvas to:

  • Me (Shih-Chieh Hsu) at for personal correspondence related to grades, health issues, etc...
  • the program coordinator at for administrator questions related to registering, overloading, etc...
  • your TA (contact information here) for other questions.
  • the Phys 123 TA coordinator (Nikolai Tolich) at for questions about your TA, or questions your TA may not be able to answer.

Course Material

You need to purchase the following items:

Getting started

  • Connect to the online homework system using the instructions found here.
  • For labs, we will use Pivot to perform video experiments.  Note that you have already paid for access to Pivot through the course fee as part of registration.  Your TA will announce details on how to get access during the first week of the quarter.

Class components

This class consists of lecture, lab, tutorial and exam components.  You can see all the components required in a given week by clicking "Modules" in the menu on the left.

Important Note: Since each exam includes questions based on the lectures, labs, and tutorials, missing a lecture, lab, or tutorial section can have an impact on your exam performance.  You should be sure to watch all lectures, and work through any lab or tutorial that you miss as soon as possible to minimize the impact on your course grade.

Lecture components:

Before each scheduled lecture you need complete the assigned reading (see schedule below).  The lectures include the following graded components:

  • Lecture reading discussion (4% of grade):
    • After completing the reading you need to complete the associated discussion assignment before 11:59 pm on the day of the assigned reading (Monday, Wednesday, and Friday).
    • These are graded based on a thoughtful attempt, not on correctness, and you will be given credit for either asking a question, answering a previous question, or discussing a part of the reading you found particularly interesting.
    • This is a place for you to answer your fellow students questions about the reading.  The TAs will read these to get a sense of common questions, and I will post a general response video, but we will not respond to individual questions.
    • Your lowest three reading discussions will be dropped.  If you miss more than three due to a valid reason (family and medical emergency etc), please contact me.
  • Lecture video engagement (4% of grade):
    • After completing the reading the you need to watch the lecture video and complete the embedded quizzes before 11:59 pm on the day of the assigned reading (Monday, Wednesday, and Friday).
    • These will be graded based on engagement, not on correctness.
    • Your lowest three video quizzes will be dropped.  If you miss more than three due to a valid reason (family and medical emergency etc), please contact me.
  • Lecture homework (8% of grade):
    • These will be due on Tuesdays at 11:59 pm, and will be based on material covered in the previous weeks reading and video.
    • You can access the lecture homework by clicking "MyLab and Mastering" in the menu on the left.

Lab components:

  • Labs (12% of grade):
    • There are eight graded lab assignments, some of which may have multiple parts.
    • Each lab assignment under "Assignments" tells you the parts to be completed in Pivot.
    • The labs are due Wednesday at 5 pm.  Before then you need to collect and analyze data from video experiments on Pivot and answer questions based on your work.
      • After you start any of the assignments, you can save your work and go back to it as many times as you want before the deadline, thus, allowing you to talk to peers or a TA, and then go back and finish.
    • Each lab assignment will be graded based on the following:
      • Adequate (2 points): All questions answered thoughtfully, and measurements closely match those expected.
      • Needs improvement (1 point): Some questions could use more explanation, and/or some measurements do not match those expected.
      • Inadequate (0 points): Lab not done or many questions could use more explanation, and/or many measurements do not match those expected.
    • If you receive 0 points or 1 point, you can do or redo up to 2 labs without asking for permission.
      • After the deadline, you will temporarily no longer be able to submit new work. Once the lab has been graded, it will be reopened, and you can complete missing work or change your responses based on feedback.  You need to contact your TA to make sure that they grade the new work.
    • If you need to make-up more than 2 labs due to a valid reason (family and medical emergency etc), contact me.

Tutorials components:

The tutorials include the following graded components:

  • Tutorial pretest (1% of grade):
    • These are designed to get you thinking about your ideas on topics covered in this course.  They are graded based on a thoughtful attempt, not on correctness.
    • These become available Friday at 3:30 PM and are due on Monday at 5 pm.
    • Once you start a pretest, you will have 15 minutes to complete it without the ability to pause.
    • Your lowest tutorial pretest score will be automatically dropped.
    • If you miss more than one tutorial pretest due to a valid reason (family and medical emergency etc), please contact me.
  • Tutorial in-class (3% of grade):
    • You need to attend and actively participate in discussion at your tutorial section (QZ section on time schedule) each week to get participation credit.  Each tutorial will be graded based on the following:
      • Adequate (2 points): Actively engaged in discussion throughout tutorial.
      • Needs improvement (1 point):  Multiple periods not engaged in discussion during tutorial.
      • Missing (0 points): Did not attend any tutorial section.
    • If you cannot attend your tutorial section in a given week, you can attend another section.  A schedule of tutorials with their Zoom links can be found here (select "12x" then select "123 Tutorial Schedule").  Be sure to contact your TA to let them know.
    • Your lowest tutorial in-class score will be automatically dropped.  However, you are still responsible for submitting the associated tutorial homework on time.
    • If you miss more than one tutorial in-class due to a valid reason (family and medical emergency etc), please contact me.   
  • Tutorial homework (8% of grade):
    • Each tutorial has homework that is due at 11:59 pm the Monday after you have worked through the tutorial.
    • You need to upload a scanned pdf file to the Canvas tutorial homework assignment.
    • You can submit one tutorial homework up to one week late without asking for permission and with no penalty, but you need to contact your TA to make sure they grade it.
    • If, due to a valid reason (family and medical emergency etc), one homework needs to be submitted more than one week late, or more than one homework needs to be submitted after the deadline, please contact me.

All important tutorial information can be found under the "Tutorial Information" menu on the left.  Once at the tutorial website select "12x" for information general to all courses in the Phys 121-122-123 sequence.  Select the link for section A under "PHYS 123" to get the schedule for all assignments specific to your class.


Exams will be done online.  The exam procedure is described here.

The following dates are preliminary and may change.

  • Midterm exam 1 on October 22nd starting between 4:55 and 5:15 pm (PDT). Once you start the exam, you will have 60 minutes to finish the exam.
  • Midterm exam 2 on November 12th starting between 4:55 and 5:15 pm (PST). Once you start the exam, you will have 60 minutes to finish the exam.
  • Final exams will be on December 15th starting between 2:25 and 2:45 pm (PST) and December 17th starting between 2:25 and 2:45 pm (PST). You can take either of the exams. Once you start the exam, you will have 110 minutes to finish the exam.

Note that there are no make-up exams.  So, students with outside professional, service, or career commitments (i.e. military service, ROTC, professional conference presentation, NCAA sports, etc.) conflicting with the exam dates must contact me early in the quarter to establish alternate examination procedures.  Exam scores for students who miss an exam without making prior arrangements will be zero.

Each exam is out of 100 points, and have three components:

  • 70 points on lecture material
  • 15 points on tutorial material
  • 15 points on lab material

Exams will count for 60% of your grade.  Your overall exam score will be based on the best of the following two methods:

  • Method 1: 20% from each of your midterms scores and 20% from your final exam score
  • Method 2: 20% from your best midterm score and 40% from your final exam score

We will design the exams such that a student who understands some of the material very well but needs some improvement in the remaining material should get a score around 65%.  If the class average on a given exam is less than 65%, then all the scores for that exam will be adjusted upward so that the average is 65%. Scores will not be adjusted downward even if the class average is higher than 65%.

If a student is found responsible for misconduct during an exam, a score of zero will be given for that exam for this student.  If the misconduct occurs during a midterm, only Method 1 is used to calculate the final grade, and Method 2 is not used.


You will get a grade of 0 for the entire course if either of the following criteria are met:

  • You receive 0 points for 3 or more lab assignments.
  • You receive less than 9 out of the 16 points possible on the lab assignments.

Otherwise your final weighted percentage is converted to a grade point using the following thresholds.

grade point course score   grade point course score   grade point course score   grade point course score
4.0 92.0 3.0 76.0 2.0 60.0 1.0 44.0
3.9 90.4 2.9 74.4 1.9 58.4 0.9 42.4
3.8 88.8 2.8 72.8 1.8 56.8 0.8 40.8
3.7 87.2 2.7 71.2 1.7 55.2 0.7 39.2
3.6 85.6 2.6 69.6 1.6 53.6    
3.5 84.0 2.5 68.0 1.5 52.0    
3.4 82.4 2.4 66.4 1.4 50.4    
3.3 80.8 2.3 64.8 1.3 48.8    
3.2 79.2 2.2 63.2 1.2 47.2    
3.1 77.6 2.1 61.6 1.1 45.6  

Reading schedule

Reading schedule.

Access and accommodation

Your experience in this class is important to me, so if you have a temporary health condition or permanent disability that requires accommodations (conditions include but are not limited to: mental health, attention-related, learning, vision, hearing, physical), please contact DRS to arrange accommodations.

Safe campus

I am committed to ensuring a safe environment on campus.  I encourage you to check out the resources available here.

Religious Accommodations

Washington state law requires that UW develop a policy for accommodation of student absences or significant hardship due to reasons of faith or conscience, or for organized religious activities. The UW’s policy, including more information about how to request an accommodation, is available at Religious Accommodations Policy ( Accommodations must be requested within the first two weeks of this course using the Religious Accommodations Request form (

Academic integrity and student conduct

The University takes academic integrity and student conduct very seriously.  Behaving with integrity and respect is part of our responsibility to our shared learning community.  Acts of academic misconduct may include, but are not limited to, cheating by working with others or sharing answers on exams.

Please note that screenshots or recordings of instructors, other students, and course materials during active video (Zoom) participation sessions are strictly forbidden.  Streaming or posting inappropriate materials on any course platform is also not allowed. 

All the course materials including exam and quiz questions, lecture notes, lecture videos are intellectual properties of the instructor and the University of Washington. Distributing them in any form without permission is forbidden.  

The University of Washington Student Conduct Code (WAC 478-121) defines prohibited academic and behavioral conduct and describes how the University holds students accountable as they pursue their academic goals.  Allegations of misconduct by students may be referred to the appropriate campus office for investigation and resolution.  More information can be found online at

If you’re uncertain about if something is academic or behavioral misconduct, ask me.  I am willing to discuss questions you might have.

Catalog Description: 
Explores electromagnetic waves, the mechanics of oscillatory motion, optics, waves in matter, and experiments in these topics for physical science and engineering majors. Lecture tutorial and lab components must all be taken to receive credit. Maximum 5 credits allowed for any combination of PHYS 116, PHYS 119, PHYS 123 and PHYS 143. Prerequisite: either PHYS 122 or PHYS 142; and either MATH 126 or MATH 134, which may be taken concurrently. Offered: AWSpS.
GE Requirements: 
Natural Sciences (NSc)
Section Type: 
Last updated: 
October 16, 2020 - 9:15pm