Physics 122 Final Exam

Here is a place for discussion of the final exam.

Practice Final Exam and Other Review Topics.

The practice final exam has been posted on Blackboard in the Course Documents section. Answers will be given in the Dec. 7 lecture slides.
In this blog thread, we will discuss any questions you have about that exam.
This thread is also the place for you to ask questions about any of the course material, old homework problems, etc.

Chapter 29+30, Problems 7-12

Material to be covered in the last day of class, December 9th.

Due Monday, Dec. 13th, at midnight.

Chapter 29+30, Problems 1-6

These problems are due on Monday, Dec. 13 at midnight. The first six problems cover material that will be discussed in class on Tuesday, Dec. 7th.

The only issue I can see in advance is with #5 (SV8.29.54). In part (a), the question asks you to find the activity of milk due to potassium. Unstated is that you want to find the activity of 1 liter of milk.

Important UPDATE announcement for Lab 10 in PHY 124

In the first part of the lab 10 manual (third paragraph above the Video (introduction to the lab), I just added a cautionary note about NOT using the Excel spreadsheet that may be on the desktop of the lab computer in A-120. (That spreadsheet had some password control in it that may cause you some problems.) You should download the Excel spreadsheet from the link in the revised manual and use that one in the lab.

If you printed out the Lab 10 manual before 3:30 this afternoon (Sunday), what you have will not have the cautionary note in it. Make sure you read the cautionary note.

If you downloaded a spreadsheet before 3:30 pm today (Sunday), you have the OLD one. Delete it and download the new one.

The online manual as well as the pdf one that can be printed out should say at the bottom of its last page:

Last modified: 2010/12/05 15:29 by pmkoch

I hope this doesn't cause any confusion. Prof. Koch

PHY 124 Lab 10 pretest is now available

The PHY 124 Fall 2010 Lab 10 pretest is now posted for you to work on and submit before the beginning of your Lab 10 section next week. You will find it in the Assignments content area in Blackboard for your PHY 124 Lab section. As explained in the course syllabus, each Lab pretest is worth 35 points. As you will see, the Lab 10 pretest consists of 3 questions. The first is worth 11 points, the second is worth 12 points, and the third is worth 12 points, making the total possible score 35 points. To do the pretest you will need to study carefully the Lab 10 manual and to re-familiarize yourself with MapleTA syntax. Go to

http://www.ic.sunysb.edu/class/phy122ps/labs/dokuwiki/doku.php?id=phy124off:phy124_main_page

and read the instructions there on the "main page". Please also click on and review the

-- "Instructions" link (you've seen this before)

-- "Uncertainty, Error and Graphs" link (and make sure you read the 17 Nov. 2010 message on the PHY 122 Course Blog about printing out this document)

and, finally, the

-- "PHY 124 Lab 10 - "Nuclear gamma rays and decay" link.

No inactive, "red" links remain on the web page. We've come to the final lab of PHY 122 / PHY 124, and it's a nice one.

As you already know, the lab pretests are prepared in the "Maple TA" software environment. You may work on each assignment as many times as you wish, but the link in the Assignments section of Blackboard for your PHY 124 section will become inactive at the starting time of your lab section. Therefore, you should not wait until just before your lab section to begin work on it. If you read the Lab Manual carefully and, there is no reason for you not to earn all 35 points for the pretest. Make sure you read carefully the instructions for each pretest problem. After each problem click on "Next" until finishing the last one, Question 4; then make sure you click on "Grade" in the Maple TA software environment. After you get your grade, you may click on "View Details" to see more about how you did. Finally, click on "Quit and Save".

Good luck!

Prof. Koch

PHY 124 Lab 9 pretest is now available

The PHY 124 Fall 2010 Lab 9 pretest is now posted for you to work on and submit before the beginning of your Lab 9 section next week. You will find it in the Assignments content area in Blackboard for your PHY 124 Lab section. As explained in the course syllabus, each Lab pretest is worth 35 points. As you will see, the Lab 9 pretest consists of 3 questions. The first is worth 5 points, the second is worth 12 points, and the third is worth 18 points, making the total possible score 35 points. To do the pretest you will need to study carefully the Lab 9 manual and to re-familiarize yourself with MapleTA syntax. Go to

http://www.ic.sunysb.edu/class/phy122ps/labs/dokuwiki/doku.php?id=phy124off:phy124_main_page

and read the instructions there on the "main page". Please also click on and review the

-- "Instructions" link (you've seen this before)

-- "Uncertainty, Error and Graphs" link (and make sure you read the 17 Nov. 2010 message on this blog about printing out this document)
and, finally, the

-- "PHY 124 Lab 9 - "Atomic Spectra" link.

The "red" links are not yet active, on purpose, but as the course develops they will be made active.

As you already know, the lab pretests are prepared in the "Maple TA" software environment. You may work on each assignment as many times as you wish, but the link in the Assignments section of Blackboard for your PHY 124 section will become inactive at the starting time of your lab section. Therefore, you should not wait until just before your lab section to begin work on it. If you read the Lab Manual carefully and, there is no reason for you not to earn all 35 points for the pretest. Make sure you read carefully the instructions for each pretest problem. After each problem click on "Next" until finishing the last one, Question 4; then make sure you click on "Grade" in the Maple TA software environment. After you get your grade, you may click on "View Details" to see more about how you did. Finally, click on "Quit and Save".

Good luck!

Happy Thanksgiving!

Prof. Koch

Chap. 28 HW assignment is now posted

The WebAssign homework problems for SV8 Chap. 28 are now posted and available. The lectures on Chap. 28 in SV8 will be on Tues., 28 Nov. and Thurs., 2 Dec. The Chap. 28 problems will be available on WebAssign until 5 pm, Mon., 6 December. Good luck! Have a nice Thanksgiving break.

Prof. Koch

Chapter 27, problems 7 through 12

These problems pertain to material in the November 23 lecture.

Note that the assignment is due on Monday, November 29th.

Chapter 27, Problems 1-6

These problems pertain to material in the November 16 lecture.

Important announcements about the PHY 124 (lab) web site and documents there

1. Quite by accident I have recently noticed that a number of you are going to the wrong web site for PHY 124, the lab part of the course. Since PHY 121/3 and PHY 122/4 are offered in three different sequences, and since the information/documents on their web sites are not identical, I can see how this might happen. I only became aware of this by noticing that the "wrong" web pages were on some of the computer screens in our lab room, A-120.

You are taking the "off" sequence of this two-semester course, viz., the one that starts as PHY 121/3 in the spring semester (Spring 2010 for most of you) and finishes as PHY 122/4 in the fall semester (the present Fall 2010 semester).

The "on" sequence begins in the fall and ends in the spring. The "summer" sequence begins in the first summer session and ends in the second summer session. You do NOT want to be going to the web sites for those sequences.

You DO want always to be going to the current, "off" sequence web site. The home page for that is (notice near the end it says phy124off )

http://www.ic.sunysb.edu/class/phy122ps/labs/dokuwiki/doku.php?id=phy124off:phy124_main_page .

2. In the lower left hand corner of the first page of each of our sets of PHY 124 web pages, e.g., in the lower left hand corner of the above web page, you will see a "Note:" that warns you about equations (sometimes) not displaying correctly when you use the web browser Internet Explorer 8.

Just yesterday I learned that when some of you print out some of the PHY 124 web pages, in particular those for the Uncertainty, Error and Graphs manual, (some) equations, indeed, are not printing out correctly, even though they may appear correctly on your computer screen. This is likely a consequence of the above Note:. Since this manual is so important for your work in the course, I have made screenshots of all the pages from my computer screen and then inserted those into files: one is a Word 2007 "docx" file. The second is a Word 2003 "doc" file. The third is a pdf file. I have posted all three of these in the Course Documents section of PHY 122 (please read carefully: it's PHY 122, not PHY 124). On my laser printer I find the Word 2007 docx file prints out most clearly. The other two are readable, but they are a little bit "fuzzier".

I strongly recommend that you print out the manual using one of these files. Then you will be sure of having the equations printed out correctly.

By the way, following the above Note:, I use the Google Chrome internet browser to view and print out the web pages for PHY 124. It renders the equations correctly. I have seen from time to time that Internet Explorer version 8, which I also use for web browsing, does not always display all equations correctly.

Prof. Koch

Helpful comment for 1c on Lab 8 pretest

The statement of the problem for 1c in the Lab 8 pretest mentions that the formula for the radius r has m, e, and B in it. It doesn't say explicitly that it also has the (magnitude of the) velocity v in it, too. If you look at SV8, Chap. 19.6, you'll see that it must have v, too.

PHY 124 Lab 8 pretest is now available

The PHY 124 Fall 2010 Lab 8 pretest is now posted for you to work on and submit before the beginning of your Lab 8 section next week. You will find it in the Assignments content area in Blackboard for your PHY 124 Lab section. As explained in the course syllabus, each Lab pretest is worth 35 points. As you will see, the Lab 8 pretest consists of 4 questions. The second is worth 8 points, and the other three are worth 9 points each, making the total possible score 35 points. To do the pretest you will need to study carefully the Lab 8 manual and to re-familiarize yourself with MapleTA syntax. Go to

http://www.ic.sunysb.edu/class/phy122ps/labs/dokuwiki/doku.php?id=phy124off:phy124_main_page

and read the instructions there on the "main page". Please also click on and review the

-- "Instructions" link (you've seen this before)

-- "Uncertainty, Error and Graphs" link
and, finally, the

-- "PHY 124 Lab 8 - "Measurement of e/m for the electron" link.

The "red" links are not yet active, on purpose, but as the course develops they will be made active.

As you already know, the lab pretests are prepared in the "Maple TA" software environment. You may work on each assignment as many times as you wish, but the link in the Assignments section of Blackboard for your PHY 124 section will become inactive at the starting time of your lab section. Therefore, you should not wait until just before your lab section to begin work on it. If you read the Lab Manual carefully and, there is no reason for you not to earn all 35 points for the pretest. Make sure you read carefully the instructions for each pretest problem. After each problem click on "Next" until finishing the last one, Question 4; then make sure you click on "Grade" in the Maple TA software environment. After you get your grade, you may click on "View Details" to see more about how you did. Finally, click on "Quit and Save".

Good luck!

Prof. Koch

Chapter 26, problems 7-12

Material for Nov. 16 lecture.

Note the comments I made on a couple of the problems in the WebAssign instructions.

Chapter 26, problems 1-6

Material to be covered in the Nov. 11 lecture.

Note the comments on a couple of the problems that I made in the WebAssign instructions.

See the PHY 122 Blackboard Course Documents for the results of Midterm 2

PHY 124 Lab 7 pretest is now available

The PHY 124 Fall 2010 Lab 7 pretest is now posted for you to work on and submit before the beginning of your Lab 7 section next week. You will find it in the Assignments content area in Blackboard for your PHY 124 Lab section. As explained in the course syllabus, each Lab pretest is worth 35 points. As you will see, the Lab 7 pretest consists of 4 questions. The first is worth 8 points, and the last three are worth 9 points each, making the total possible score 35 points. To do the pretest you will need to study carefully the Lab 7 manual and to re-familiarize yourself with MapleTA syntax. Go to

http://www.ic.sunysb.edu/class/phy122ps/labs/dokuwiki/doku.php?id=phy124off:phy124_main_page

and read the instructions there on the "main page". Please also click on and review the

-- "Instructions" link (you've seen this before)

-- "Uncertainty, Error and Graphs" link
and, finally, the

-- "PHY 124 Lab 7 - Interference and Diffraction" link.
The "red" links are not yet active, on purpose, but as the course develops they will be made active.

As you already know, the lab pretests are prepared in the "Maple TA" software environment. You may work on each assignment as many times as you wish, but the link in the Assignments section of Blackboard for your PHY 124 section will become inactive at the starting time of your lab section. Therefore, you should not wait until just before your lab section to begin work on it. If you read the Lab Manual carefully and, there is no reason for you not to earn all 35 points for the pretest. Make sure you read carefully the instructions for each pretest problem. After each problem click on "Next" until finishing the last one, Question 4; then make sure you click on "Grade" in the Maple TA software environment. After you get your grade, you may click on "View Details" to see more about how you did. Finally, click on "Quit and Save".

Good luck!

Prof. Koch

Chapter 25, Problems 6-12

These problems relate to material to be covered in class on Tuesday, Nov. 9th.

I have written comments on several of the problems in the instructions that you will see when you look at the assignment. Please read them before you work on the assignment.

Chapter 25, Problems 1-5

I have written comments on several of the problems in the instructions that you will see when you look at the assignment. Please read them before you work on the assignment.

These first five problems relate to material covered in class on Thursday, Nov. 4th.

Answer keys for Midterm 2 are posted in Course Documents in Blackboard

The answer keys for Form 0, Form 1, Form 2, and Form 3 are posted separately in Blackboard Course Documents. Please make sure you click on the correct link. I don't know if I will receive the graded midterm 2 exam scores from the Faculty Center opscan office before the end of the week.

Prof. Koch

Chapter 24, Problems 7-12

This original blog post has gotten pretty well buried, so I'm restarting it. In fact, as of Tuesday morning, there have not been any questions or discussion relevant to Chapt. 24 posted!

I am extending the due date for this assignment to Thursday (Nov. 4), 3:00 PM.

These problems are from the second half of SV8 Chapter 24, and cover the material of the November 2 lecture.

Chapter 24, Problems 1-6

This original blog post has gotten pretty well buried, so I'm restarting it. In fact, as of Tuesday morning, there have not been any questions or discussion relevant to Chapt. 24 posted!

I am extending the due date for this assignment to Thursday (Nov. 4), 3:00 PM.

These problems are from the first half of SV8 Chapter 24, and (mostly) cover the material of the October 28 lecture.

In the third question (SV8 P24.7), you only need to answer part a. (I can't easily remove part b from the assignment, but I don't want you to struggle with it. That's why this question is assigned two points and the total assignment looks like it has 13 points. But your score will be recorded out of a maximum of 12, and there is no extra credit for that part b.) In that problem, note that the ANGLES ARE NOT SMALL. I discussed this problem near the end of lecture on Oct. 28th.

Today's review session; answer key to practice midterm problems

Echo 360 recorded it, but it turned off at 3 pm in the beginning/middle of going over problem 15. The technology used to capture the static images of the handwritten notes I put on the ppt slides via the pen-pad at the podium did not work fully. The quality of the handwritten images is not very good, and the system did not write it in a "lasting" way to the ppt slides. I don't know why. You can see the handwritten notes/solutions on the ppt slides in Echo 360, but only through problem 14. The answer key to all the problems on the practice midterm 2 is below:

1. A
2. D
3. Only true answer is C.
4. E
5. A
6. B, D
7. D
8. D
9. C
10. C
11. B, D
12. B,E
13. C
14. C
15. C
16. A
17. D
18. B
19. C
20. C

Good luck on Monday. Prof. Koch

Blackboard is down. Until it's back up, follow link below to practice midterm.

http://www.ic.sunysb.edu/Class/phy122ps/Fall2010phy122/Practice Midterm 2 PHY 122 Stony Brook University PM Koch 20101028.pdf

It's too long to fit on one line, and I don't know how to make it an active link in the blog, so make sure you cut and paste the whole thing without any spaces or deletions.

Prof. Koch

The practice midterm 2 is now posted

The practice midterm is now posted. See the Course Documents web page in Blackboard. Sorry for the delay. Good luck. See you Sunday at the review session in ESS 001, noon - 2 pm, to go over the solutions to it and answer other questions you may have. See the course blog for room assignments and other information about the midterm on Monday, 1 November, 8:30 - 10 pm. Prof. Koch.

Review session (noon-2 pm Sunday in ESS 001) and Practice exam for midterm 2 (delayed)

As announced yesterday in lecture, we will have a review session for midterm 2 in ESS 001 (our usual lecture hall) on Sunday, 31 October, from noon - 2 pm. It will be recorded on the Echo 360 system for later viewing by those of you who can't make it to the session or want to see again what went on. I will go over the solutions to the practice midterm and then answer questions from students who have them.

At lecture yesterday I promised the practice exam for midterm 2 to be made available by "this evening" (Wednesday), but it looks like I'm not going to make it by then. I'm working steadily on it and now expect to make it available by tomorrow (Thursday) morning.

Midterm 2: day/time/rooms

As you already know, the second midterm exam (on material in SV8 Chaps. 19 through 23 and in Labs 4 though 6) will be held on Monday, 1 November 2010, 8:30 - 10 pm.

Rooms and what to bring/not to bring: We have four rooms available for alternate seating, so please pay attention to where you're supposed to go in the alphabetical (by last names) sub-lists below. (For the cases where more than one student has the same last name, I've included the first name in the alphabetic filtering.) Each room will be filled to or near to capacity taking into count the alternate seating. Please be on time, bring more than one pencil for filling in the bubble sheet, bring your University ID (or, if you have lost/misplaced it, another form of ID that has a recent picture of you on it), bring a "standard" calculator (this does not include calculator operations built into, say, a smart phone or a netbook computer -- none of those allowed), and bring, if you want, one page of notes (both sides allowed) on whatever material you want personally to write down on it for helping you during the exam. During the exam: no voice/texting or any other cellphone activity. Turn off your cellphone and keep it out of sight.

Please be on time. Anyone coming in late will not get extra time. It's your responsibility to arrive well before the exam and wait quietly outside the lecture room being used for the exam until you're let in by the proctors.

Humanities 1003: Ahmed through Gerges

Javits 101: Ghotra through Li, Amy

Javits 103: Li, Joseph through Petruc

Javits 111: Pinto through Zhu, Judy

Exam forms: Be sure to record all necessary information on the bubble sheet including the "form number" of the exam according to the procedure used for the first midterm. We will remind you what that procedure is.

You should take home your one page of notes and the exam sheets, but of course NOT the bubble sheet!

Practice SV8 Chap. 23 HW: for MT2 prep.

Every problem in SV8 Chapter 23 is in that assignment. Scores will not be counted towards your grade - the problems are for you to practice is you want. This thread is a place to discuss any of those problems. In referring to any problem here, please identify it with the information that is at the right side of the blue bar above the problem, e.g., SERCP8 23.P.031

Practice SV8 Chap. 22 HW: for MT2 prep.

Every problem in SV8 Chapter 22 is in that assignment. Scores will not be counted towards your grade - the problems are for you to practice is you want. This thread is a place to discuss any of those problems. In referring to any problem here, please identify it with the information that is at the right side of the blue bar above the problem, e.g., SERCP8 22.P.005

Practice SV8 Chap. 21 HW: for MT2 prep.

Every problem in SV8 Chapter 21 is in that assignment. Scores will not be counted towards your grade - the problems are for you to practice is you want. This thread is a place to discuss any of those problems. In referring to any problem here, please identify it with the information that is at the right side of the blue bar above the problem, e.g., SERCP8 21.P.023

Practice SV8 Chap. 20 HW: for MT2 prep.

Every problem in SV8 Chapter 20 is in that assignment. Scores will not be counted towards your grade - the problems are for you to practice is you want. This thread is a place to discuss any of those problems. In referring to any problem here, please identify it with the information that is at the right side of the blue bar above the problem, e.g., SERCP8 20.P.015

Practice SV8 Chap. 19 HW: for MT2 prep.

Every problem in SV8 Chapter 19 is in that assignment. Scores will not be counted towards your grade - the problems are for you to practice is you want. This thread is a place to discuss any of those problems. In referring to any problem here, please identify it with the information that is at the right side of the blue bar above the problem, e.g., SERCP8 19.P.020.

SV8, Fig. 22.14: Useful graph for Lab 6, Part I.3

I just sent this to all students in the PHY 122/PHY 124 email list. Look at that email to get the jpg attachment of the figure described below.

************

Attached to this email is a jpg picture file of a screenshot I made of Fig. 22.14 in SV8. It shows graphs of n vs. wavelength lambda in nm for three different materials. One of these, acrylic (plastic), is the material used to make the prism you'll be using in Part I of Lab 6. Even though the the Lab 6 manual labels Part I.3 "Dispersion: qualitative only", you should try to be as quantitative as possible. This week's WebAssign HW problem 5 (which is SV8, Ch. 22, Prob. 32) is a quantitative problem on dispersion in a prism. You can use it as the basis for understanding Lab 6 Part I.3 in a more quantitative way. For this you'll need the dispersion curve for acrylic (plastic) in the attached Fig. 22.14.

Prof. Koch

PHY 124 Lab 6 pretest is now available

Please excuse getting this email twice, but I thought it doesn't hurt to make sure you get the word. I've posted this announcement on the PHY 122 Blackboard site, your PHY 124 lab section Blackboard site, and I've sent it via email from both Blackboard sites.

The PHY 124 Fall 2010 Lab 6 pretest is now posted for you to work on and submit before the beginning of your Lab 6 section next week. You will find it in the Assignments content area in Blackboard for your PHY 124 Lab section. As explained in the course syllabus, each Lab pretest is worth 35 points. As you will see, the Lab 5 pretest consists of 4 questions. The first is worth 5 points, the second is worth 5 points, the third is worth 15 points, and the fourth is worth 10 points, making the total possible score 35 points. To do the pretest you will need to study carefully the Lab 6 manual and to re-familiarize yourself with MapleTA syntax, which is used in the third question. Go to

http://www.ic.sunysb.edu/class/phy122ps/labs/dokuwiki/doku.php?id=phy124off:phy124_main_page

and read the instructions there on the "main page". Please also click on and review the

-- "Instructions" link (you've seen this before)

-- "Uncertainty, Error and Graphs" link (you've seen this before, and it's important for the third questions in the Lab 6 pretest)
and, finally, the

-- "PHY 124 Lab 6 - Reflection, Refraction and Images" link.

The "red" links are not yet active, on purpose, but as the course develops they will be made active.

As you already know, the lab pretests are prepared in the "Maple TA" software environment. You may work on each assignment as many times as you wish, but the link in the Assignments section of Blackboard for your PHY 124 section will become inactive at the starting time of your lab section. Therefore, you should not wait until just before your lab section to begin work on it. If you read the Lab Manual carefully and, there is no reason for you not to earn all 35 points for the pretest. Make sure you read carefully the instructions for each pretest problem. After each problem click on "Next" until finishing the last one, Question 4; then make sure you click on "Grade" in the Maple TA software environment. After you get your grade, you may click on "View Details" to see more about how you did. Finally, click on "Quit and Save".

Good luck!

Prof. Koch

Combined Ch.22,23 HW: 10-12 (from Ch.23)

Combined Ch.22,23 HW: 7-9 (from Ch.23)

Combined Ch.22,23 HW: 4-6 (from Ch.22)

Combined Ch.22,23 HW: 1-3 (from Ch.22)

Clicker scores: 10/19/10 and generally

Yesterday, 10/19/10, I made a mistake by ending clicker question 2 way too early. Some students asked yesterday after lecture and later by email or blog if I would correct this. The answer is yes. I posted the clicker grades yesterday but corrected them just now this morning. I deleted the former Blackboard gradebook column "CPS 10/19" and put in its place "CPS 10/19 edited". I gave credit for clicker question 2 to any student whose clicker registered any response to clicker questions 1 or 3 independent of whether that clicker had responded to 2. I did not give credit to any student whose clicker did not respond to question or question 3 because I took that as evidence for not yet being present/responding in the lecture hall.

Generally: Some students have asked about the maximum clicker score each lecture. I gave the incorrect answer to at least one student. Here is the correct answer: The maximum score for each lecture is 100 points. If ten questions are given and scored (including the freebie), each is worth 10 points. If nine questions are given and scored, each is worth 11.11 points. If eight questions are given and scored, each is worth 12.5 points, and so on.

I have also posted this as an announcement on Blackboard and sent it to all students by email.

Prof. Koch

Lab 5 pretest is now available (PHY 124 part of course)

The PHY 124 Fall 2010 Lab 5 pretest is now posted for you to work on and submit before the beginning of your Lab 5 section next week. You will find it in the Assignments content area in Blackboard for your PHY 124 Lab section. As explained in the course syllabus, each Lab pretest is worth 35 points. As you will see, the Lab 5 pretest consists of 2 questions. The first is worth 14 points, and the second is worth 21 points, making the total possible score 35 points. To do the pretest you will need to study carefully the Lab 5 manual and to re-familiarize yourself with MapleTA syntax, which is used in both questions. Go to

http://www.ic.sunysb.edu/class/phy122ps/labs/dokuwiki/doku.php?id=phy124off:phy124_main_page

and read the instructions there on the "main page". Please also click on and review the

-- "Instructions" link (you've seen this before)

-- "Uncertainty, Error and Graphs" link (you've seen this before, and it's important for both questions in the Lab 5 pretest)
and, finally, the

-- "PHY 124 Lab 5 - AC Circuits " link.

The "red" links are not yet active, on purpose, but as the course develops they will be made active.

As you already know, the lab pretests are prepared in the "Maple TA" software environment. You may work on each assignment as many times as you wish, but the link in the Assignments section of Blackboard for your PHY 124 section will become inactive at the starting time of your lab section. Therefore, you should not wait until just before your lab section to begin work on it. If you read the Lab Manual carefully and, there is no reason for you not to earn all 35 points for the pretest. Make sure you read carefully the instructions for each pretest problem. After each problem click on "Next" until finishing the last one, Question 2; then make sure you click on "Grade" in the Maple TA software environment. After you get your grade, you may click on "View Details" to see more about how you did. Finally, click on "Quit and Save".

Good luck!

Prof. Koch

Chap. 21 HW: Problems 9-12

Chap. 21 HW: Problems 5-8

Chap. 21 HW: Problems 1-4

Extension of Chap. 20 HW to 15 Oct.

I already put this on the Blackboard announcements page for PHY 122 and sent it to all students by email:

PHY 122 students,

Responding to an email from one of the students, I wrote the following:
Yes, [at yesterday's = Tuesday, 12 October lecture] I didn't cover all of inductors and didn't cover the RL circuit because the microphone-volume problem at the beginning of lecture cost me the 10 minutes that I needed at the end. By my reckoning, problems 9, 10, 11, and 12 involve the above material. I did cover part (b) for problem 9. All these four problems are direct applications of formulas in the text, and most of them are very similar to worked example problems in sections 20.7 and 20.8 of SV8 Chap. 20. I just checked the Chap 20 HW grades for all students in the course; most students have worked out these problems, but to be fair to all, I've decided to extend the deadline for the Chap. 20 problems to 5:00 pm on Friday, 15 October. At the beginning of tomorrow's (Thursday, 14 October) lecture, I'll cover the rest of the material about inductors and the RL circuit.

Prof. Koch

Lab 4 pretest went live mid-afternoon Saturday, 9 Oct.

You should have received an email reminder. I hope you will find Lab 4 to be a particularly interesting one, but there is a lot to do. Please make sure you're well prepared and work diligently during the lab period.

Chapter 20, Problems 9-12

Chapter 20, Problems 5-8

Chapter 20, Problems 1-4

Practice Chapter 18

Every problem in SV8 Chapter 18 is in that assignment. Scores will not be counted towards your grade - the problems are for you to practice is you want. This thread is a place to discuss any of those problems. In referring to any problem here, please identify it with the information that is at the right side of the blue bar above the problem, e.g., SERCP8 18.P.018.

Practice Chapter 17

Every problem in SV8 Chapter 17 is in that assignment. Scores will not be counted towards your grade - the problems are for you to practice is you want. This thread is a place to discuss any of those problems. In referring to any problem here, please identify it with the information that is at the right side of the blue bar above the problem, e.g., SERCP8 17.P.018.

Practice Chapter 16

Every problem in SV8 Chapter 15 is in that assignment. Scores will not be counted towards your grade - the problems are for you to practice is you want. This thread is a place to discuss any of those problems. In referring to any problem here, please identify it with the information that is at the right side of the blue bar above the problem, e.g., SERCP8 16.P.018.

Notice the SV8 problem numbers in the WebAssign HW assignments

This may be helpful to all of you for the WebAssign HW. I think that most of you refer to the WebAssign problem numbers (1,2,...,12) when doing the weekly assignments. You should also pay attention to the information at the right-hand side of the "blue bar" for each HW problem. For example, for the Chap 19 HW, it will say SerCP8 19.P.0xy, where xy is a two-digit number giving the problem number at the end of, in this case, Chapter 19 (of Serway and Vuille, Classical Physics, 8th edition). It will be helpful in many of the problems to look at what's in the book, not just what's on the WebAssign HW "pages" you view on the computer screen. Reason: there may be (a) figures(s) in the book, near the text of the problem, that will be useful to you for solving the problem. A case in point is Chap. 19, Problem 38 (which is the WebAssign #8 for Ch. 19 HW). To understand the geometry/layout of the "mass spectrometer" mentioned in the problem, look at the right-hand side of Fig. 19.36. This is what's envisioned for Problem 38. In this case, even more useful is Example 19.6 on p. 641 of SV8. Fig. 19.22 shows the pictorial layout of the mass spectrometer, and the example problem is very similar to Problem 38.

Chapter 19, Problems 9-12

Chapter 19, Problems 5-8

Chapter 19, Problems 1-4

In the first problem, the range between maximum and minimum comes from the relative direction of the magnetic field and the electron's motion.

Practice Chapter 15

Every problem in SV8 Chapter 15 is in that assignment. Scores will not be counted towards your grade - the problems are for you to practice is you want. This thread is a place to discuss any of those problems. In referring to any problem here, please identify it with the information that is at the right side of the blue bar above the problem, e.g., SERCP8 15.P.018.

Practice Midterm Exam

This thread is for discussion of problems in the practice midterm exam, which is posted in Blackboard in Course Documents.

Lab 3 pretest is now available

I posted the announcement for the Lab 3 pretest availability for all PHY 124 sections and sent it to each of your email addresses (the ones that Blackboard accesses). As usual, the pretest assignment will be available to you until your lab section begins.

Prof. Koch

Chapter 18, Problems 10-12

Problems with resistors and capacitors, from Section 18.5.

Chapter 18, Problems 7-9

These problems require application of Kirchhoff's rules for more complicated DC circuits. See section 18.4

Chapter 18, Problems 1-6

These problems pertain to sections 18.1, 18.2, and 18.3. You should be able to deal with all of them using combinations of series and parallel resistors.

Note that question 4 part C asks for the power delivered by the battery, but the dimension given with the answer is Amperes. That should be Watts. (Doesn't affect how you approach the problem -- I just mention it to avoid possible confusion.)

Chap 17, Problem 12

This problem is a bit tricky. Start by drawing a diagram, and note that the question asks for the power delivered to the cleaner, which would exclude power that heats the extension cord.
Also, see my latest post about the need to calculate intermediate results to an accuracy much better than 1%. You should be safe with six significant digits as you are working.

Chap 17, problems 9 - 11

Problems from SV8 Section 17.6. The language of #10 (Problem 17.36) is a bit ambiguous. Part b should say, "What percentage of the power generated by the power station does this loss represent."

Chap 17, Problems 7 and 8

Problems from Section 17.5.

Chapter 17, problems 4-6

These problems are from Section 17.4. For the fifth one (SV 17.12), you might find yourself with two equations involving length and area of the wire: the given mass gives you L*A, and the resistance gives you L/A. Multiply those two equations together and it eliminates A.

Chapter 17, Problems 1-3

For 2 and 3, you need to convert a given mass or density of metal to charge or charge density. I think it's easiest to visualize this as a unit conversion problem, for example, the density of Al is 2.7 g/cm^3, which you want to convert to electrons/m^3. So multiply by unity in various forms to clear the dimensions. For example (1 mole / 27 g of Al), (How many atomis is it? / mole), (conduction electrons / atom), ...

Lab 2 pretest is now available

Please see the Announcements web page in Blackboard for your PHY 124 lab section. To avoid clutter, I took down the previous announcement about the Lab 1 pretest. The Lab 2 pretest announcement will remain up for each lab section until that section meets to do Lab 2. I'll do the same for future labs. As I did for Lab 1, I sent the announcement via email to each student in each section. If you did not get it, something is not right with your email. This could be that the University does not have the email address that you are (now) using. It's up to you to correct this. Instructors using Blackboard to send email to students do not see the email address being used for each student.

Chapter 17

I'll break this up into more threads soon, but if anybody is getting a head start, there are a couple of things I want to point out. In a couple of problems, you will need to find densities, atomic numbers, etc. of certain elements. This kind of info is readily available on the web, and you have a periodic table with some of this info in the back of your book. Likewise, the book contains a table of resistivities and thermal coefficients of resistivity (page 577).
The statement of part of the 10th question (SV8 17.36) is poorly phrased; part b) should read, "what fraction of the power that is generated at the power station does this loss represent."
Careful with dimensions throughout. Look at the dimensions furnished with the answers. millimeters, micrometers, percent, ...

PHY 124 Lab 1 pretest

Students (and TA staff) in all lab sections should have received email on Tuesday (7 Sept) night about the Lab 1 pretest being posted in the Assignments section of Blackboard for your lab section of PHY 124. The email was the same Announcement that also appeared on Blackboard. I know that many of you have logged in and at least started the Lab 1 pretest, which exists within the Maple TA "plugin" for Blackboard. There are 5 multiple-part questions in the pretest; each question is worth a maximum of 7 points, giving 5x7=35 points maximum in all. Partial credit is given for partially correct answers, but there is no limit on how many times you may re-do the pretest. You may check how you did on each question, and when you're done with an attempt on the whole pretest, you may check your overall grade for it. I logged in as a student, took the pretest, and did all of these steps. So far, as the instructor I am able to monitor how many students are logged in on the pretest for each section, but a software glitch prevents me from seeing the pretest grades for each student. The Blackboard support staff is now working to correct that.

Make sure you do not wait until the last minute to complete the Lab 1 pretest because, as was contained in the Announcement/email, you will cease to have access to the pretest at the time your lab section begins.

Good luck!

Prof. Koch

Chapter 16, question 12

This question, SV8 problem 16.52, has some problems in its wording. First, the capacitor is made from two strips of aluminum foil, separated by paraffin-coated paper. The question wants you to think about the capacitor unrolled, so that there are two flat plates, separated by one layer of the dielectric. What are the dimensions of that configuration in order to have the given capacitance? (Then, as an editorial note, the statement of the problem goes on to say that if you put in another piece of paper and roll the thing up as illustrated, it will actually have twice the capacitance because now charge accumulates on both sides of each plate, essentially doubling the active area.)

Chapter 16, questions 10, 11

These two questions refer to material in SV8 section 16.9.

Chapter 16, questions 7-9

These two questions come from SV8 sections 16.6 and 16.7.

Chapter 16, Questions 3 through 6.

These questions are from SV8 sections 16.2, 16.3, and 16.4. Please try to look at them before the September 7th class.

Chapter 16, Questions 1, 2

Remember that this homework assignment is due on Wednesday, September 15th at 5:00 PM.
This thread is to discuss the first two questions, which come from SV8 section 16.1

Chapter 15, questions 10-12

These three questions are from SV8 sections 15.6, 15.8, and 15.9. The whole assignment is due on Tuesday, September 7th at 3:30 PM.

Chaper 15, questions 5-9

These five questions are from SV8 section 15.4. The whole assignment is due on Tuesday, September 7th at 3:30 PM.

Chapter 15, Questions 1-4

These four questions are from SV8 section 15.3. The whole assignment is due on Tuesday, September 7th at 3:30 PM.

Welcome to Physics 122

Once the course gets going, this will be a forum for discussing homework problems and the like. You can post questions and comments, and your instructors will be following closely.