Physics 132
Exam 1
September 14, 2004
INSTRUCTIONS: Write your NAME and your LECTURE (01: 8:30/Eskildsen, 02: 10:40/Bunker,
03: 3:00/Jessop) on the front of the blue exam booklet. The exam is closed b
General Physics II (10320)
Exam I Sept. 12, 2006
Page 1 of 4
Instructions: Write your NAME and your SECTION (01 = 8:30/Eskildsen, 02 = 3:00/Tang) on
the front of the blue exam booklet. The exam is clo
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C H A P T E R 1 4 Fluid Mechanics
32. You are a passenger on a spacecraft. For your survival and
comfort, the interior contains air just like that at the surface of the Earth. The craft is coastin
S E C T I O N 1 4 . 6 Bernoullis Equation
433
Example 14.7 Niagara Falls
Each second, 5 525 m3 of water ows over the 670-m-wide
cliff of the Horseshoe Falls portion of Niagara Falls. The water is appr
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C H A P T E R 1 4 Fluid Mechanics
Thus, at the end of the time interval, the segment of uid consists of the unshaded portion and the blue shaded portion at the upper right.
Now consider forces exe
Problems
excavation. This foundation wall is 0.183 m away from the
front of the cellar hole. During a rainstorm, drainage from
the street lls up the space in front of the concrete wall,
but not the ce
S E C T I O N 1 4 . 6 Bernoullis Equation
435
decreases. This Bernoulli effect explains the experience with the truck on the highway at
the opening of this section. As air passes between you and the t
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C H A P T E R 1 4 Fluid Mechanics
When P is much greater than P0 (so that the term 2gh
can be neglected), the exit speed of the water is mainly
a function of P. If the tank is open to the atmosphe
Summary
437
Figure 14.23 Because of the deection of air, a spinning golf ball experiences a lifting
force that allows it to travel much farther than it would if it were not spinning.
on the translatio
C H A P T E R 1 4 Fluid Mechanics
430
Finally, the density of the crown is
c
mc
m g
7.84 N
c
Vc
Vc g
(1.02 104 m3)(9.80 m/s2)
7.84 103 kg/m3
To nalize the problem, from Table 14.1 we see that the
C H A P T E R 1 4 Fluid Mechanics
432
particles cannot ow into or out of the sides of this tube; if they could, then the streamlines would cross each other.
Consider an ideal uid owing through a pipe
S E C T I O N 1 4 . 4 Buoyant Forces and Archimedess Principle
This equation tells us that the fraction of the volume of a oating object that is below the uid surface is equal to the ratio of the dens
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Andy Sacks/Getty
S E C T I O N 1 4 . 5 Fluid Dynamics
Figure 14.14 Laminar ow around an automobile in a test wind tunnel.
Thus far, our study of uids has been restricted to uids at rest. We now tu
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C H A P T E R 1 4 Fluid Mechanics
B
h
To understand the origin of the buoyant force, consider a cube immersed in a liquid
as in Figure 14.8. The pressure Pb at the bottom of the cube is greater th
C H A P T E R 1 4 Fluid Mechanics
x 1
F1
A1
A2
x 2
F2
David Frazier
424
(b)
(a)
Figure 14.4 (a) Diagram of a hydraulic press. Because the increase in pressure is the
same on the two sides, a small for
S E C T I O N 1 4 . 4 Buoyant Forces and Archimedess Principle
427
Quick Quiz 14.3 Several common barometers are built, with a variety of
uids. For which of the following uids will the column of uid i
C H A P T E R 1 4 Fluid Mechanics
426
Using Equation 14.2, we nd that the force exerted on the
shaded strip of area dA w dy is
dF P dA g(H y)w dy
Answer We know from Equation 14.4 that the pressure
va
Questions
439
18. A person in a boat oating in a small pond throws an anchor overboard. Does the level of the pond rise, fall, or
remain the same?
ond entrance at ground level is open to almost stagna
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C H A P T E R 1 4 Fluid Mechanics
2. The sum of the pressure, kinetic energy per unit volume, and gravitational potential energy per unit volume has the same value at all points along a streamline
S E C T I O N 5 . 8 Forces of Friction
then the acceleration is up the incline for the block and
downward for the ball. Also note that the result for the acceleration (5) can be interpreted as the mag
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C H A P T E R 5 The Laws of Motion
The acceleration given by (3) can be interpreted as the ratio
of the magnitude of the unbalanced force on the system
(m 2 m 1)g, to the total mass of the system
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C H A P T E R 5 The Laws of Motion
What If? Imagine that the force F in Figure 5.12 is applied
toward the left on the right-hand block of mass m2. Is the
magnitude of the force P12 the same as it
S E C T I O N 5 . 7 Some Applications of Newtons Law
(2)
a
2.00 m/s
F
1 (40.0 N)
g
9.80 m/s
T ma y mg mg
ag
y
1
2
y
g
2
1
48.2 N
If a is downward so that ay 2.00 m/s2, then (2) gives us
T Fg
ag
S E C T I O N 5 . 7 Some Applications of Newtons Law
n mg cos gives us n mg cos 90 0. This is consistent
with the fact that the car is falling downward next to the
vertical plane but there is no inter
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C H A P T E R 5 The Laws of Motion
y
n
mg sin u
m g cos u
x
u
u
Fg = m g
(a)
(b)
Figure 5.11 (Example 5.6) (a) A car of mass m sliding down a frictionless incline.
(b) The free-body diagram for th
Oscillations and
Mechanical Waves
PA R T
2
e begin this new part of the text by studying a special type of motion called
periodic motion. This is a repeating motion of an object in which the object
co
Problems
449
h
d
Figure P14.75
Answer to Quick Quizzes
14.1 (a). Because the basketball players weight is distributed
over the larger surface area of the shoe, the pressure
(F/A) that he applies is re
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C H A P T E R 1 4 Fluid Mechanics
L
Valve
closed
Valve
opened
v
L
(a)
(b)
ent masses (Fig. P14.73). At sufciently low temperatures all
the spheres oat, but as the temperature rises, the spheres
si
Problems
447
Mount Everest rise above the surface of such an atmosphere?
61.
Review problem. With reference to Figure 14.5, show
that the total torque exerted by the water behind the dam
about a horiz
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C H A P T E R 1 4 Fluid Mechanics
Additional Problems
54. Figure P14.54 shows a water tank with a valve at the bottom. If this valve is opened, what is the maximum height
attained by the water str