A special note to 303K students and other users of this library. We hope you will be an active user of the IQ-library this semester. In using the IQ-libary, if you have a query on any of the questions, please post your concerns on the board. We hope that you can be an active participant to bring to IQ-library up-to-date. Postings may include, although not limited to:
I plan to visit this board on a regular basis. However, if you need my immediate attention, in addition to submitting a posting here, please also email me at chiu@physics.utexas.edu. For the posting, the inclusion of your name is not required. On the other hand, the inclusion of your name together with your email address may allow me to further communicate with you. -- C. Chiu
Present board:
Mon Sep 4 13:32:53 CDT 2000
Mon Mar 27 19:50:52 CST 2000
Mon Mar 27 14:30:37 CST 2000
Fri Feb 11 16:46:52 CST 2000
Tue Feb 1 02:57:04 CST 2000
Tue Dec 14 12:08:10 CST 1999
Tue Dec 14 12:03:43 CST 1999
Wed Dec 1 01:26:13 CST 1999
Chiu's Comments 11-24-99
Wed Nov 10 18:58:00 CST 1999
IQ question: 9.6.2
Wed Nov 10 14:31:42 CST 1999
Dr. Chiu's comment on
the query of IQ10.8.3 (sumbitted on Nov 2 17:47:24): The moment of initial
of a rod about a rotating axis, which is perpendicular to the rod and it
passes through its center of mass, is given by mL**2/12. On the other hand,
the moment of inertial of the same rod about a different rotating axis,
which is parallel to the former rotating axis and which passes through
one of the end points, is given by mL**2/3. These two expressions are related
by the law of parallel axis: I_end=I_cm + mD**2. For the present case it
reads mL**2/3=mL**2/12+m(L/2)**2.
Tue Nov 9 07:25:17 CST 1999
Dr. Chiu's updates: Thanks
for those who have contributed to the IQ-board. Following should be fixed.
IQ9.6.2: The figure needs to be modified. Please change small l (i.e. the
length of the height and of the width) to capital L. Let d=L/2. Add the
label A at the center and the label D at the middle of the bottom line.
IQ10.8.6: The m2-equation just above the table of multiple choices should
read m2g-T2=m2a. Presently g is missing. IQ:11.3.1: In the figure please
label the highest point of the trajectory by the letter P. IQ11.5.4: Choice
2 should be 2/3, not 3.
Tue Nov 9 07:10:25 CST 1999
On 10.8.3 isn't the moment
of inertia of a rod I=ML^2/12 not divided by three as in the answer? It
says 12 in the book...
Tue Nov 2 17:47:24 CST 1999
on question 9.6 -2 Where
is this so called point A it doesn't even exist on the diagram?
Tue Nov 2 17:26:04 CST 1999
The point A in the drawing
for question 9.6.2 is missing.
Sun Oct 31 16:53:19 CST 1999
IQ Questions 6.1.3, 7.3.1,
and 8.4.7 have been corrected according to Dr. Chiu's instructions. Question
9.4.4's link has been fixed. ---R. Brown
Wed Oct 27 21:53:45 CDT 1999
Hello, Question 9.4.4
has a broken link. Thanks.
Mon Oct 25 12:59:04 CDT 1999
On question 11.5.4, the
answer is 2/3, but 2/3 is not one of the answer choices. Also, there is
a misspelling in the question.
Wed Oct 20 14:34:31 CDT 1999
IQ 8.4.7: In explanation,
it has ans=4. Please change to: ans=1. -- C. Chiu
Mon Oct 11 09:54:58 CDT 1999
IQ: 6.1.3 Thanks for
the error report on this question on the board. Do send me an email after
you have posted the error report so that I can reply to your report in
a timely fashion. Please also include your name and email address, if you
wish, so that I know who you are and I can further communicate with you
through email if needed. Anyhow, the coordinate axes and their labels in
the figure of are inccorect. Now have x(up) and y(right). They should be
changed to x(left) and y(up). -- C. Chiu
Mon Oct 11 08:02:02 CDT 1999
Correction to 7.3.1.
In explanation: 1) Now have from 0 to A, should be changed to: from x=0
to x. 2) Now have Ans=4, should be changed to: Ans=3. In extra: Now have
from A to 0, should be changed to from x=x1 to x=0. -- C. Chiu
Mon Oct 11 07:32:36 CDT 1999
Question 6.1.4's link
has been fixed. ---R. Brown
Sun Oct 10 20:43:06 CDT 1999
IQ 6.1.3 has mislabeled
x- and y-axes if you follow the
Tue Oct 5 16:44:16 CDT 1999
Question 6.1.4's link
does not work properly. Thanks. Alvin Leung alleung@mail.utexas.edu
Sun Oct 3 14:33:14 CDT 1999
IQ Questions 2.5.2, 2.5.6,
3.3.2, 3.4.1, 5.7.1 have been updated as per Dr. Chiu's comments. ---R.
Brown
Tue Sep 28 02:51:03 CDT 1999
IQ 5.7.1 Strongman: Please
revise the problem statement to include following qualifying statement
as indicated by the () parenthesis. ... pulled horizontally as shown. (You
may assume that the angle between each strand of the rope and the horizontal
direction is less then 0.1 radian) . The tension in each strand would be
... --- C. Chiu
Wed Sep 22 07:37:01 CDT 1999
IQ 5.7.1 Strongman: Insert
the following qualifying statement as indicated by the square brackets.
Wed Sep 22 07:33:18 CDT 1999
IQ 5.7.1 Strongman: Insert
the following qualifying statement as indicated by the <> brackets.
Wed Sep 22 07:31:24 CDT 1999
Srujanad, with your premise
that va and vb are negative, Ans=2 is correct. I should have qualified
by saying that va and vb are speeds not velocities. This question will
be modified. Thank you for your imput. C. Chiu
Thu Sep 16 06:02:18 CDT 1999
Dr. Chiu, For IQ 2.5.2,
I think the Ans=2 because a=-g. In the equation g=[vb-va]/tab, vb and va
are going to be negative values because the velocity is downwards. Could
you please clarify this, Srujana, Srujanad@hotmail.com
Wed Sep 15 09:08:50 CDT 1999
IQ-3.3.2 typo: The choices
should be 1,2, 3 and 4 instead of 1, 2, 3 and 3. -- C. Chiu
Sun Sep 12 23:11:16 CDT 1999
IQ-2.5.6: In the explanation,
there is a typo: t_AB/t_AO should be 1/sqrt(3), not sqrt(3). -- C. Chiu
Sun Sep 12 23:04:39 CDT 1999
please comment on homework
questions for hw 3; it seems confusing the way the questions are asked
Fri Sep 10 19:52:43 CDT 1999
IQ: 3.4.1 A trip: Answer1
should be: acos(alpha)-bsin(beta)-c. Notice is should be -b, not +b. --
C. Chiu
Thu Sep 9 06:42:48 CDT 1999