Final Exam
Phys 111
Fall 2002
Version A
Section______
NAME_________________________________________________________________SCORE __________
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The exam is closed book and closed notes.
Only one 8 1/2 x 11 formula sheet is permitted
Gravitational acceleration g = 32 feet per second-squared
1 pound (1 lb) = 0.45 newtons.
Make sure you put your name on the SCANTRON form.
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1. Two forces act on a 80-kg particle: 300N north and 500 N east as shown in the figure. The magnitude of the resultant
acceleration is closest to:
A. 3.75 m/s2.
B. 5.75 m/s2
C. 6.55 m/s2.
D. 7.29 m/s2
E. 9.00m/s2
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2. A 2-kg book is given an initial velocity of 4.9 m/s on a horizontal wooden surface and slides 2.5 meters before coming to
rest. The coefficient of kinetic friction is most nearly:
A. 0.075
B. 0.184
C. 0.375
D. 0.490
E. 0.625
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3. A block M has a mass 10 kg and hanging block m has a mass 5 kg . The block
M is moving down a frictionless incline at constant speed. What is the incline
angle .
A. 100
B. 200
C. 3 00
D. 400
E. 500
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4. A small object of mass m = 0.5 kg on the end of a light cord is initially held at rest at the end
of a horizontal cord of length L = 0.8 m, as shown. The object is then released. The tension in
the cord at the lowest point of the swing is closest to:
A. 4.9 N
B. 9.8 N
C. 14.7 N
D. 19.6 N
E. 24.5 N
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5.
A small object slides along the frictionless loop-the-loop with a diameter
of 4.3 m. What minimum speed must it have at the top of the loop?
A. 12.2 m/s
B. 9.75 m/s
C. 7.3 m/s
D. 6.1 m/s
E. 4.6 m/s
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6. A horizontal force, F, exerted on a body, which weighs 8 N and moves on a horizontal surface at constant speed. The
coefficient of friction between the body and the surface is 0.25. The work done by F (in Joules) when the body has moved
12 m is:
A. 0
B. 2
C. 10
D. 24
E. 96
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7.
A cart of mass m, traveling on a horizontal air track with speed v, collides with a stationary cart of mass 2m. The
carts stick together. The impulse exerted by one cart on the other has magnitude:
A. 0
B. 2mv/3
C. mv
D. 3mv/2
E. 2mv
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8. A small object, released from a height of 15 m, slides along the frictionless
loop-the-loop with a diameter of 4.3 m. What is its speed at the top of the loop?
A. 14.5 m/s
B. 9.75 m/s
C. 7.3 m/s
D. 6.1 m/s
E.
4.6 m/s
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9. A wheel starts from rest and has an angular acceleration of 4.0 rad/s2 . The time it takes to make 10 revolutions is:
A. 0.50 s
B. 0.71 s
C. 1.4 s
D. 1.8 s
E. 5.6 s
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10. Three identical objects of mass M are fastened to a massless rod of length L as
shown. The rotational inertia about one end of the rod of this array is:
A.
B.
C.
D.
E.
ML2/2
ML2
3ML2/2
5ML2/4
3ML2
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11. A disk with a rotational inertia of 5.0 kg ×m2 and a radius of 0.25 m rotates on a fixed axis perpendicular to the disk and
through its center. A force of 2.0 N is applied tangentially to the rim. As the disk turns through half a revolution the work
done by the force is:
A. 1.6 J
B. 2.5 J
C. 6.3 J
D. 10 J
E. 40 J
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12. A 6-kg particle moves to the right at 4 m/s as shown. Its angular
momentum in kg ×m2 /s2 about the point O is:
A. zero
B. 288
C. 144
D. 24
E. 249
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13. A playground merry-go-round has a radius of 3.0 m and a rotational inertia of 600 kg × m2 . It is initially spinning at
0.80 rad/s when a 20-kg child crawls from the center to the rim. When the child reaches the rim the angular velocity of the
merry-go-round is:
A. 0.61 rad/s
B. 0.73 rad/s
C. 0.80 rad/s
D. 0.89 rad/s
E. 1.1 rad/s
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14. A picture P of weight W is hung by two strings as shown. The total upward
pull of the strings on the picture is:
A.
B.
C.
D.
E.
2 W cos
T sin
T cos
2T sin
2T cos
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15. The 150-lb ball shown is suspended on a string AB and rests against the frictionless vertical wall
. The string makes an angle of 30° with the wall. The tension in the string is:
A.
B.
C.
D.
E.
173 lb
520 lb
300 lb
600 lb
none of these
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16. A 100-lb uniform vertical boom is attached to the ceiling by a hinge, as shown. A 200lb weight W and a horizontal guy wire are attached to the lower end of the boom as
indicated. The tension T in the horizontal guy wire is:
A. 86 lb
B. 100 lb
C. 172 lb
D. 200 lb
E. 300 lb
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17. Let M denote the mass of Earth and let R denote its radius. The ratio g/G at Earth's surface is:
A. R2/M
B. M/R2
C. MR2
D. M/R
E. R/M
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18. The mass of an object:
A. is slightly different at different locations on the Earth
B. is a vector
C. is independent of g
D. is the same for all objects of the same size and shape
E. can be measured directly and accurately on a spring scale
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19. A planet is in circular orbit around the Sun. Its distance from the Sun is four times the average distance of Earth from
the Sun. The period of this planet, in Earth years, is:
A. 4
B. 8
C. 16
D. 64
E. 2.52
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20. A particle moves back and forth along the x axis from x = -xm to x = +xm, in simple harmonic motion with period T. At
time t = 0 it is at x = -xm. When t = 0.75T:
A. it is at x = 0 and is traveling toward x = +xm
B. it is at x = 0 and is traveling toward x = -xm
C. it is at x = +xm and is at rest
D. it is between x = 0 and x = +xm and is traveling toward x = -xm
E. it is between x = 0 and x = -xm and is traveling toward x = -xm
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21. An object attached to one end of a spring makes 20 vibrations in 10 seconds. Its frequency is:
A. 2 Hz
B. 10 s
C. 0.05 Hz
D. 2 s
E. 0.50 s
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22. A 0.25-kg block oscillates on the end of the spring with a spring constant of 200 N/m. If the system has a total energy of
6.0 J, then the amplitude of the oscillation is:
A. 0.06 m
B. 0.17 m
C. 0.24 m
D. 4.9 m
E. 6.9 m
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23. If the length of a simple pendulum is doubled, its period will:
A. halve
B. double
C. increase by a factor of
2
D. remain the same
2
E. decrease by a factor of
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