TAM 202, Fall 2002, Old News

Most recent old news first (see main page for new news):

* (Dec. 21, 02) Grading is done. Corrections of past errors is complete. Final grades have been assigned. If you have some questions or think we have made an error of some kind or would like to look at your final exam: HOLD ON TO YOUR HAT. If you can wait until all TAs are back at the end of January it would be best. If you cannot, please wait until January 6. Between now and then we are all over the world and cannot discuss your issues. If we have made an error we will be happy to correct it and correct your grade. All manner of grade data and statistics are in this .zip folder. To open the .xls file therein first open Excel, then view all files, then open. The exact details of how your grade was computed are in the 'readme', 'excel' and 'matlab' files there. If you can't decompress that .zip file you can at least find all our grade data for you, including your final exam score, and your final letter grade in this .html file.
Final exam and solutions are posted. Grading comments will be posted in January.
* Hydrostatics puzzle has been solved (Nov 1, 2002). Two solutions are posted but a prize remains open (still open on 12/21/02) for a second winner who can use the concept of moment-of-inertia in the solution.
* Solutions to the last HW are now posted.
The summary sheet you will get with your final exam has been improved slightly (bigger font, irrelevant topics deleted). If you plan to use this sheet in the exam, make sure to know your way around it before then.
* All of our recorded grades for you this semester are on this spread sheet sorted by your prelim grades (an Excel sheet zip compressed).There are surely some mistakes on this sheet. Please find them and communicate with your TA about them. Don't panic. When the course is finally graded these grades will be posted again so you can check that the corrections were made.
Some practice problems are on the makeup prelim 1, makeup prelim 2 (no solutions available) and the
  Homework exam. Look at the Homework exam solutions if you get stuck.
If you did not get an email about how to earn 1 point on your total grade by doing a course
  evaluation, get on, or back on, ask to get on the course email list immediately.
Some comments on the final exam:
  -note that there are topics which have been covered in TAM 202 in past semesters which we  
   have not coverred and which will thus not be on the final exam:
      >pressure vessels
      >Mohr's circle
      >VQ/It formula for shear in beams
  -the final exam will come with a formula sheet something like this.
Office hours for the study period are posted.
* The final exam conflict with CS 100 is resolved by taking the CS 100 makeup. The final exam 3-exams-in-24-hrs conflict between TAM 202, Physics 213 and MAE 221 is resolved by taking the MAE 221 makeup.The Econ 102 conflict is avoided by taking the Econ makeup. If you have another final exam conflict please contact Joe Burns immediately.
* The homework from the last week of classes, including the synthesis question, is due Tuesday Dec 10.
* If you are sure you can do the homework but are worried about passing the class, on Tuesday Dec 10 (note change of date) at 10 AM you can take a homework exam to get a guaranteed C-. Five problems will be given. Each will be a homework problem, a prelim problem, or a part thereof but possibly with the variable names changed, the numbers changed, and the figure may be rotated. None will be from the homework due Dec 10. Bring a calculator. If you get four of the five problems completely correct you get a guaranteed C- independent of all other course work. If you do not get four problems completely right this extra exam is ignored in your grade calculation. Bring food. You will have 6 hours to work. Closed book and closed notes. Thurston 204. Contact Andy Ruina (alr3) if you plan to take this test.
If you missed Prelim 1 or 2 the makeup is on Monday Dec 9 at 9 AM in Thurston 204. Contact Professor Burns (jab16) if you plan to take this makeup.
* The homework due Tuesday Dec 3 covers the lecture from Monday before Thanksgiving, but not from Wednesday 11/27 before Thanksgiving. This is as written on the course syllabus.
* Class will be held as usual on Wednesday 11/27 before Thanksgiving.
* Office hours Wednesday 11/27 afternoon will be held if anyone shows up by 2:40 PM. They will be cancelled if no-one shows up by then.
* Office hours will be held as usual on Sunday Dec 1.
* Prelim 2 grading comments have been posted. If you question the grading of your prelim please a) learn to do the problem correctly, b) understand your errors in detail, c) read the grading comments, d) informally discuss your issue with one of the course staff, e) turn your prelim in to your TA for regrading with a note explaining your reasoning. Do not write on your exam in any way.
* If you missed a lab you can make it up this week (Wed Nov 20 - Friday Nov 22) from 2:30pm-4:30pm. If possible show up Wed for lab 1, Thurs for lab 2 and Friday for lab 3.
* The trampofoil puzzle has been solved.
The Stressalyzer problem S4 is due Nov 26, not Nov 19 or Nov 24.
* Some comments on problem 3.4-10:
a) In this problem the book uses "rate of twist" to mean the total rotation of one end relative to the other divided by the total length. That is the book means "average rate of twist". b) Please imitate the sample problem, but do not quote formulas from it. For example, instead of reducing the integral to a cubic and solving that numerically, you could evaluate the integral numerically (as a function of the parameter still in the integrand).
* Half the course email list was deleted by accident. If you did not get an email on Sunday Nov 11 about the lab and the posting of prelim 2 solutions please contact alr3@cornell.edu.
Lab 4 on buckling has been replaced with an on-line virtual lab on torsion. You need not read lab 4 in the pdf or paper manual or prepare the lab 4 pre-lab questions. If you have questions about the web
site, what you are supposed to do there, and the report please contact Peeyush Bhargava, pb83@cornell.edu, 5-0824. If you have questions about the theory please contact your lab TA.
Prelim 2 "solutions" are posted here and on the Syllabus page.
* The homework graders have posted comments on the homeworks. These might
help you think about what to do and what to avoid in your work on future homeworks
and on the exams. Here they are (also available from the syllabus page).

* Special Fall-Break week      office hours in the Conway Room, Thurston 102   
  Starting      Sunday Oct 12. (Reverting to the previous schedule Sunday Oct 19)
     Sunday       none         
     Monday   1:30 -  3:30 Don Conway
              2:30 -  4:30 Tian Tang
              8:30 - 10:30 Bao Zhongping
       Wed   12:15 -  1:15 Joe Burns
              1:45 -  2:30 Joe Burns
              2:30 -  4:30 Andy  Ruina
              4:00 -  6:00 Peeush Bhargava
              4:30 -  5:30 Andy Ruina (in Statics lab, "extra section")
              6:00 -  8:00 Vijay Muralidharan
              8:00 - 10:00 Pankaj Porwal  

* The homework after fall break is due Thursday Oct 17 by 9 AM.
* Prelim 1 things:
  – Comments on the grading, and on common student errors, are on the syllabus page and here.
Grade statistics: median =74, the mode is about 87 (score with the highest slope on the cumulative distribution).
     More statistics details posted on the exam page, the syllabus page, and here (an m-file to run).
If you feel you should have done better, consider this advice from pages viii-ix of the Ruina and Pratap book
    (appropriately interpret the parts of the advice that specifically concern that book).
Also, attend the extra section, its there for you, and consider asking for a tutor from engineering advising.
The homework do Oct 22 asks you to do parts of prelim 1 again.
     Download the prelim from the "Exams and grading" page below.
No matter how you did on the prelim you should do these problems perfectly in every way.
* The syllabus mistakenly assigned prob 6.3 for HW due Oct 17. That has been corrected to 6.13.
* Two small lecture corrections (to fix your notes):
    a) The handout on moment about an axis (review before prelim 1) has a twice repeated penographical error.
      This is corrected in blue on the .pdf file of that handout that you can download here or from the syllabus page.
   b) At the end of the 11:15 lecture on Wed Oct 9 a student asked if the two friction forces were equa in the
      2-by-4-on-a-rod coffee cup stand example. The correct answer is: "At the case of impending slip, so F_f = mu N,
      they are equal because the two normal forces are equal in magnitude (by horizontal force balance). But if the
      coffee cup is further out, so slip is no longer impending, the normal forces are still equal, but the friction
      forces may or may not be (because slip is no longer impending and you know only that F_f <= mu N, not
      that F_f= mu N, and the problem is statically indeterminate)."
* The bridge puzzle below has been solved (9/26/02). The solution is posted.
Some comments on homework grading, from the graders, are on the syllabus page.
All exams in this class will be such that it will be possible to get 100% on all questions with no use of Matlab.
On the other hand, unless otherwise stated for a problem, if you reduce the solution to correct Matlab commands that
would yield a correct solution, and you have noted how to interpret the Matlab output, you can
(depending on the quality and clarity of the problem setup) get full credit for a problem.
Please study this cover page for the coming prelim.
Prelim rooms:
           Bao and Tang students go to Hollister B14;
          Viay, Pankaj, and Peeush students go to Kimball B11.
        Early makeup in Thurston 204 (not Thurston 201).
Please sit in columns (one student behind another) with a space between each pair
of students. Put all coats, books, notes, bags etc at the side of the room. At your seat you should
have writing tools and food only.
* HW 5 solns will be posted by 6 PM Monday Sept 30. Fully describe any way you use those
solutions in the homework you hand in. Any fully acknowledged use is allowed.* In order to help the TAs and graders and encourage your better work habits and ability to get right answers, the policies at the top of the syllabus page will be strictly enforced starting with the homework being handed in on Sept 24.
Some hints on HW due Sept 24:
4.49: a few section cuts are needed. If you pick nice ones and nice force or moment balance
     equations you never have to solve several equations in several variables.
4.62: you can use three-fold symmetry along the diagonal of the force line of action.
      Also you can cross off 6 zero-force members.
* Mistake in board notes in lecture of 9/16 in 11:15 lecture: "Make section cut to cut bar of interest and at most two other bars."
You may be a winner. The Collegetown bridge puzzle. See contest rules below.
Pre-lab questions (coompleted before the lab) are to be handed in at the start of your lab meeting.
  This will be strictly enforced starting with lab 2.
HW 3 due Sept 17 is harder than the previous homeworks, some tips:
   -Do the truss problems before you do the 3D problems,
   -Use your fancy calculator or Matlab if you are over-challenged by many linear equations in many unkowns,
   -Note you are only asked for one bar force in 4.27 (and it can be found very easily).
   -Prob 3.90 can be handed in one week. Now dueby Sept 24.
* This past week (9/4) the Wednesday extra section accidentally met in the Dynamics lab instead of the Statics lab.
  Let me (alr3) know if this threw you off. The few of us had fun (really) with resultants and cross products.
Because of the bookstore under-order of the Meriam and Kraige Statics text:
   + We put 3 copies on reserve in Carpenter library;
   + We put one desk copy in the office hours room (The Conway room, Thurston 102);
   + We scanned and put the first three sets of problems online (on the course syllabus page).
     (In order to respect the book copyright we will stop this posting when the books arrive.)
* The new TA for section 1 (Thursday  9:05) is Pankaj Porwal,   please note on your homework.
  The new TA for section 2 (Thursday 10:10) is Zhongping Bao,  please note on your homework.
Lab 20 has been rescheduled to meet a week later, see the course lab page for the present schedule.
* People who missed lab Monday and Tuesday Sept 2 & 3 have got emails from their TAs.
* Read lab 0 casually, but don't hand anything in for it.
* If you have got no email about this class write to ruina@cornell.edu to get on the email list* The broken links to the lab pages have been fixed.
* Room changes:
     - The 10:10 lecture is in Thurston 203 (not Kimball B11)
Section 4 on Fri 9:05 - 9:55 meets in Upson 109 (not 111a)
* Sections will meet
Thursday and Friday August 29 and 30 (before any lectures have been given).
* All course information will be in lecture or on this WWW page. This course has no paper handouts.
The first homework is due Tuesday September 3 unless you have not been able to get a book.
  Then you can hand it in a week late with a note on the top saying "Late because I couldn't get to a copy of the text book."
If you did not get a "welcome to TAM 202" email" let us know (ruina@cornell.edu)
  so you can get on the course email list.

Write to TAM 203 Staff