Exam 2 Fall 2007 Solutions - PHYSTCS 221 Fall 2007 EXAM2...

PHYSTCS
221
EXAM 2: November 14,
Fall 2007
2007 8:00pm-10:00pm
Name (printed):
Recitation I nstructor:
INSTRUCTIONS:
Section #
This exam contalns
25 multiple-choice questions plus 2 extra credit questions, each worth 3
points. Choose one answer only for each question. Choose
the best answer
to each question.
Answer all questions.
Allowed material:Before
turning over this page, put away all materials
except for pens, pencils,
erasers, rulers and your calculator.
There is a formula
sheet attached at the end of the exam.
Other copies of the formula sheet are not allowed.
Galculator: In general, any calculator, including
calculators that perform graphing,
is permitted.
Electronic devices that can storelarge amounts of text, data or equations
(like
laptops,
palmtops,
pocket computers, PDA or e-book readers) are NOT permitted.
lf you are unsure whether or not
your calculator
is allowed for the exam, ask your TA.
How to fill in the bubble sheet:
Use a number 2 pencil. Do NOT use ink.
lf you did not bring a pencil, ask for one.
Writeand
fill in the bubbles corresponding
to:
-
Your
last name, middle initial,
and firstname.
-
* *
Your lD number
(the
middle 9 diqits on vour ISU cardl
* *
-
Special codes K to L are your recitation
section. (Honors
section, please enter 24).
Always use two digits (e.9. 01, 09, 11, 13)
Please turn over your bubbte sheet when you are not writing on it.
lf you needto change any entry, you must completely
erase your previous
entry. Also, circle
your answers on this exam. Before handing
in your exam, be sure
that your answers on your
bubble sheet are what you intend
them to be. You may also copy down your answers on a piece
of paper to take with you and compare with the posted
answers. You miy
use the table at the
end of the exam for this.
When you are finished with the exam,place all exam materials,
including the bubble sheet, and
the exam itself,
in your folder and return
the folder to your recitation
instruitor.
No cell phone calls allowed. Either
turn off your cell phone or leave
it at home. Anyone
answering a cell phonemust hand
in theirwork;their exam
is over.
Besf of luck, Paul Canfield and
paula
Herrera

28. Which of the following changes
to an oscillating system will
cause the smallest
change in the system'speriod?
A) For a spring / mass system, double thq mass.
B) For a spring / mass system, double the spring constant.
$For
a simple pendulum (point mass on a string), double the length of the string.
'p)/For
a simple pendulum (point mass on a string), double the mass.
D
All of the above changes affect the period in the same manner.
29. An insulating
rod with charge
Q
is placed at distance
d froman uncharged
metal
surface. The electrostatic
force between
therods is:
A) Zero.
B) Attractive
it
Q
>
0, repulsive if
e
<
A.
A
Attractiv
e if
Q
(
0, repulsive if
Q
>
0.
(92Attractive, independently of the sign of
e.