Time and Date Stamps (logged): 01:32:07 08-29-2008
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Precalculus II
Technical Physics (Phy 111) Final Exam
Completely document your work and your reasoning.
You will be graded on your documentation, your reasoning, and the
correctness of your conclusions.
Test should be printed using Internet Explorer. If
printed from different browser check to be sure test items have not been cut off. If
items are cut off then print in Landscape Mode (choose File, Print, click on Properties
and check the box next to Landscape, etc.).
Name and Signature of Student
_____________________________
Signed by Attendant, with Current Date and Time:
______________________
If picture ID has been matched with student and name as
given above, Attendant please sign here: _________
Instructions:
- Test is to be taken without reference to text or
outside notes.
- Graphing Calculator is allowed, as is blank paper or
testing center paper.
- No time limit but test is to be taken in one
sitting.
- Please place completed test in Dave Smith's folder,
OR mail to Dave Smith, Science and Engineering, Va. Highlands CC, Abingdon, Va.,
24212-0828 OR email copy of document to dsmith@vhcc.edu,
OR fax to 276-739-2590. Test must be returned by individual or agency supervising test. Test is not to be returned to student after it has been taken. Student may, if proctor deems it feasible, make and retain a copy of the test..
Directions for Student:
- Completely document your work.
- Numerical answers should be correct to 3 significant
figures. You may round off given numerical information to a precision consistent
with this standard.
- Undocumented and unjustified answers may be counted
wrong, and in the case of two-choice or limited-choice answers (e.g., true-false or
yes-no) will be counted wrong. Undocumented and unjustified answers, if wrong, never get
partial credit. So show your work and explain your reasoning.
- Due to a scanner malfunction and other errors some
test items may be hard to read, incomplete or even illegible. If this is judged by
the instructor to be the case you will not be penalized for these items, but if you
complete them and if they help your grade they will be counted. Therefore it is to
your advantage to attempt to complete them, if necessary sensibly filling in any
questionable parts.
- Please write on one side of paper only, and staple
test pages together.
Test Problems:
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Problem Number 1
An object is released from rest at a distance of .62 meters below its equilibrium
point. If the object is subjected to a net restoring force with force constant 52 N
/ m, and if the mass of the object is 5.5 kg, then
- What is the centripetal acceleration, in m/s ^ 2, of the reference point on the
circle which models the resulting simple harmonic motion?
- What acceleration would you expect for the object at the instant it reaches an
extreme point?
- Explain in your summary why you would expect the object itself to undergo this
acceleration at the extreme positions in its cycle.
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Problem Number 2
An object originally moving at a constant speed is acted upon for a specified time by a
constant force of 180 Newtons. At the end of the specified time the force is removed
and the object proceeds at a new constant velocity.
- If the object traveled a distance of 90 meters while under the influence
of the force, and if there was no dissipation of energy, then by how much would the
kinetic energy (abbreviated KE) of the object increase?
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Problem Number 3
Over an interval of .09 seconds, the velocity of an object of constant mass 2 Kg is
observed to change from 4 m/s to 2.524009 m/s.
- Find the average force on the
object using the Impulse-Momentum Theorem.
- Verify your results using your
knowledge of uniformly accelerated motion.
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Problem Number 4
From the length and mass of a simple pendulum we determine that the restoring
force constant is k = m g / L. A bullet of mass 25 grams and moving at
unknown velocity is quickly absorbed into the 13.9 kg mass of the pendulum, which
is initially at rest. The pendulum absorbs the bullet, and its mass is
observed to move to a maximum displacement of .086 meters from the equilibrium
position.
Find the velocity of the mass immediately after absorbing the bullet, and the
velocity of the bullet immediately before impact. Assume that no dissipative forces act on
the system after the collision.
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Problem Number 5
An object with mass 15 kilograms, initially at rest, is acted upon by a force of 231
Newtons.
- If the force acts for .07 seconds, what will be KE increase of the object,
based on its velocity change?
- During the .07 seconds, based on the distance it
travels, how much work is done by the net force on the object?
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Problem Number 6
If velocity increases by 15 meters per second per
second, how many seconds does it take for velocity to increase by 3 meters per second?
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Problem Number 7
Two objects collide and remain stuck together after
collision.
One object has mass 26 kg and is moving in the
positive direction at 23 m/s and the other has mass 26 kg and and moves at 18 m/s in the
negative direction.
- What is their total momentum, and what will be the
velocity of this system immediately after collision?
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Problem Number 8
An object is moving at a constant velocity of 4 m/s before an acceleration phase, and
at another constant velocity after the acceleration phase.
- If during the acceleration phase the velocity changes at a rate of 9 m/s
per second, and if the acceleration phase lasts 5 seconds, then what will be the increase
in velocity?
- What will be the second constant velocity?
- What will be the average velocity?
- How far will the object travel during the acceleration phase?
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Problem Number 9
What are x and y the components of the vector obtained when we add force vector
A, with magnitude 4 meters and angle 149.9 degrees, to the force vector B whose
angle and magnitude are 275.2 degrees and 5.6 meters?
- What are the magnitude and angle of this resultant vector?
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Problem Number 10
What are x and y the components of the velocity
vector obtained when we add the two following velocity vectors:
- vector A, with x and y components -8.3 m/s and -8.3
m/s, and
- vector B whose x and y components are -8.3 m/s and
-2.7 m/s?
What are the magnitude and angle of the resultant
vector?