If you start working on the homework only the day before it is due, everything that can go wrong, will go wrong.

Frequently Asked Questions about PHYSICS 121 Spring 1997


How can we contact you?

By email:  rajeev@pas.rochester.edu
In person:  B&L 351  at  Tue. 11:00-12:00

Please come by my office  to tell me how you are
doing  in the course. Come especially if you are having difficulties.
Even if you cant make it during my office hours, please come by when you can
and see if I am free. Some of you have been coming to see me regularly on Tuesdays and Thursdays after class. I encourage you to continue to do that and bring your more reticent friends with you. The more I hear from you the better I can fine tune the
course to your needs.

Send me your comments on any aspect of the course by email.
Why is physics so difficult?

Physics is different from all other branches of knowledge (except for mathematics) in that all facts can be derived  from a small number  of axioms (basic laws). If you appreciate this and learn to derive every equation from the basic laws, physics will make sense.   For example all of mechanics can be deduced from Newton's three laws. (Can you think of another field where all you really need to know are three laws and everything else can be deduced from them? )  Learning to think
logically and mathematically takes practice and hard work.


I registered for the course late. How do I get my homework?


I don't see a homework under my name. What am I doing wrong?

For the first week you can use someone  elses homework questions and hand in the answer ALONG WITH  A COPY OF THE  QUESTIONS  to your TA in recitation. (You must of course do the homework  yourself.)He will enter it into the computer. Email your TA at qiyue@pas.rochester.edu with your student ID number and name, so we can add you to the class list. You might also  look under your first name rather than last name; sometimes the computer confuses the two.
If you see such an error, email your TA.
Where can I get help for homeworks?

At the CAPA workshops: most afternoons in  Room 304: see a detailed schedule posted at the door.If you have a grade less than 50% for homeworks, you are required to attend them.

The homeworks make me think ; it isn't enough just to know the physics. Is that fair?

Duh??  Learning physics is not just about memorizing some facts.  Using what you know in specific situations is just as important.  The homeworks are  supposed to  make you think.

This has been my favorite question so far. ;-)
Why are the homeworks so hard?

May be you haven't been going to recitation and the CAPA workshops?
You must  go to the recitation   and the CAPA
workshops  (Room 304).  You should also consider signing up
for a study group organized by the learning assistance center .
(Look in the main web page of the course under Study Group for more details. )
You  can also ask me questions during my office hours Tue. 11:00 -12:00.

Why are the homeworks so easy  compared to the exams?

 The homeworks are not meant to prepare you for the exams.
They test one kind of skill: whether you can apply the formulas of physics to various practical situations. It is good that you find the homeworks easy; that means you are above average in the class. The exams also test whether you can derive those formulas. You can have a perfect score in the homeworks and still do poorly in the exams.

I took the course last time and failed. This time around the homeworks seem
tougher. What do I do?

Clearly you need to put more time into the course than you did last time.
If you don't miss  a single recitation, lecture or CAPA work shop ,  and work
hard  I guarantee you that you will pass this course. It may be  even tougher
a third  time around, so make  the best of the second chance.
I went home for the weekend so I couldn't do the homework. Can I  submit it
late for  partial credit?
I had another exam on Wednesday so I couldn't do the homework. Can I have more time?

No.  You have  almost a  whole week to do the homework.
It wouldn't be fair to those who submitted the answers in time if I gave you extra time.

When I look at my homework all I find is a jumble of letters and numbers. What is wrong?

The homeworks are contained in a POSTSCRIPT file. It will be readable only after you print it, following the GOPHER instructions handed out to you.


Will there be makeup exams?

There will be no makeup exams.

The only exception could be  a documented medical emergency.

Why are we required to know integral calculus although our calculus course hasn't
yet done integrals?

I went over the rudiments of integral calculus in Lecture 9.  Some basic rules of integration are summarized in the notes to that lecture. This is all the  integral
calculus you need to know to do the problems
I have assigned in homework and exams.

Why am I doing so badly in the  exams  when I am doing fine in homeworks?

The CAPA homeworks test  your ability to apply what you learned to some specific
situations. The exams also test if you know where the formulas come from: to be able
to derive them. You must read the lecture notes (and the book ) and be able to
reproduce the arguments. This is often harder than just working out problems.

I feel I am one of the better students in the class. Yet I have to work as hard as the students who are behind me. Am I doing something wrong?

No. To just pass the course you probably dont have to work too hard. But if you want to get an A or close to it you have to work really hard. I expect
that even the very best students have to struggle in order to get an A.  Even if you are getting a 100% grade in the homeworks
you will probably find the exams difficult.


What is the meaning of the grading scheme?

I expect that most students will do well in the homeworks; they mostly
are applications of  physics formulas to everyday situations.
If you do well in the homeworks and  adequately in the exams you will get a C.
To get better you have to be able to show that you can  derive the formulas from the fundamental principles of physics. For example, if  you know that the moment of inertia of   a solid disk is 0.5 MR^2 (or know
where to look it up) you can solve the homework problems that use that fact.
(Knowledge at this level will get you a C.)
In the exams I test whether you can derive that fact from the basic definition of moment of inertia. If you can do that also you are a candidate for an A.
I never had physics before. How can I make up for that?

May be you should  study with someone else in the class who has taken
physics before.  It will be a while before you are comfortable with a whole
new way of looking the world. Dont despair, give yourself time to adjust.

I never had trigonometry before. What do I do?

You have to give yourself a crash course in trigonometry. It is much easier
to learn than calculus, so we dont give a course on trigonometry. Find
a textbook that you are comfortable and read up  on it. See me
during office hours if you need help.

By the  way, write to your highschool and get them to start teaching
trigonometry  and  calculus.


What the hell are CAPA and GOPHER?
CAPA is a computerized method for  grading homeworks and GOPHER  a system
for distributing  them.

 CAPA Instructions
 GOPHER Instructions

What is my student ID number?

The Student ID number is just your Social Security number.

What is the CAPA ID number?


What is the PIN number?

You must first print the homework out following the GOPHER instructions. Each person has a personalized homework set, with a number called the PIN number printed at the top. This is the same as your CAPA ID.

What is the user name for CAPA? What is the password?

The user name (or login name) for CAPA is phy121s7. The password is your professor's name.


When do the labs start? How do I sign up for one?

Labs start the second week of classes. Sign-up sheets are posted in the Bausch and Lomb Building, near Room 261 .


Should I buy the hardcover edition or the paperback edition of the textbook?

A student just brought to my attention that the paperback edition is divided into Parts and not Volumes. Part I of the paperback is only about half the  contents of Volume I of the hardcover. Make sure that you have all the  21 chapters of the Volume I avaliable to you.

Do I have to buy the recommended books and computer disks?

I only require that you have the textbook and study it. The other books and programs are recommended only in the sense that, if you find them to your taste, you can use them. You should decide yourself if they are worth the extra cost.