water flows smoothly toward the right. The radii of the pipe sections are indicated. In which arrangements is the net work done on
a unit volume of water moving from the leftmost section to the
rightmost section (a) zero, (b) positive, and (c) negative?
8 A rectangular block is pushed
face-down into three liquids, in
turn. The apparent weight W app of
the block versus depth h in the
three liquids is plotted in Fig. 14-26.
Rank the liquids according to their
weight per unit volume, greatest
first.
9 Water flows smoothly in a horizontal pipe. Figure 14-27 shows
the kinetic energy K of a water element as it moves along an x axis
that runs along the pipe. Rank the
three lettered sections of the pipe
according to the pipe radius, greatest first.
10 We have three containers with different liquids. The gauge
pressure p g versus depth h is plotted in Fig. 14-28 for the liquids.
In each container, we will fully submerge a rigid plastic bead.
Rank the plots according to the magnitude of the buoyant force
on the bead, greatest first.
2.00R
2.00R
R
(1)
3.00R
R
2.00R
(2)
2.00R
3.00R
R
(3)
R
R
3.00R
(4)
5
The teapot effect. Water
poured slowly from a teapot spout
can double back under the spout for
a considerable distance (held there
by atmospheric pressure) before
detaching and falling. In Fig. 14-23,
the four points are at the top or bottom of the water layers, inside or
outside. Rank those four points according to the gauge pressure in the water there, most positive first.
6 Figure 14-24 shows three identical open-top containers filled to
the brim with water; toy ducks float in two of them. Rank the containers and contents according to their weight, greatest first.
Figure 14-24 Question 6.
(a)
(b)
(c)
Figure 14-25 Question 7.
Figure 14-26 Question 8.
W app
h
a
b
c
406
CHAPTE R 14 FLU I DS
Water
flow
d
c
b
a
Spout
Figure 14-23 Question 5.
K
x
A
B
C
Figure 14-27 Question 9.
p g
h
a b
c
Figure 14-28 Question 10.
Module 14-1 Fluids, Density, and Pressure
•1
A fish maintains its depth in fresh water by adjusting the
air content of porous bone or air sacs to make its average density
the same as that of the water. Suppose that with its air sacs collapsed, a fish has a density of 1.08 g/cm
3
. To what fraction of its expanded body volume must the fish inflate the air sacs to reduce its
density to that of water?
•2 A partially evacuated airtight container has a tight-fitting lid
of surface area 77 m
2
and negligible mass. If the force required to
remove the lid is 480 N and the atmospheric pressure is 1.0 ϫ 10
5
Pa, what is the internal air pressure?
•3
Find the pressure increase in the fluid in a syringe when a
nurse applies a force of 42 N to the syringe’s circular piston, which
has a radius of 1.1 cm.
SSM
ILW
•4 Three liquids that will not mix are poured into a cylindrical container. The volumes and densities of the liquids are 0.50 L, 2.6 g/cm
3
;
0.25 L, 1.0 g/cm
3
; and 0.40 L, 0.80 g/cm
3
. What is the force on the
bottom of the container due to these liquids? One liter ϭ 1 L ϭ
1000 cm
3
. (Ignore the contribution due to the atmosphere.)
•5
An office window has dimensions 3.4 m by 2.1 m. As a
result of the passage of a storm, the outside air pressure drops to
0.96 atm, but inside the pressure is held at 1.0 atm. What net force
pushes out on the window?
•6 You inflate the front tires on your car to 28 psi. Later, you measure
your blood pressure, obtaining a reading of 120/80, the readings being
in mm Hg. In metric countries (which is to say, most of the world), these
pressures are customarily reported in kilopascals (kPa). In kilopascals,
what are (a) your tire pressure and (b) your blood pressure?
SSM
7 Figure 14-25 shows four arrangements of pipes through which
Tutoring problem available (at instructor’s discretion) in WileyPLUS and WebAssign
SSM Worked-out solution available in Student Solutions Manual
• – ••• Number of dots indicates level of problem difficulty
Additional information available in The Flying Circus of Physics and at flyingcircusofphysics.com
WWW Worked-out solution is at
ILW Interactive solution is at
http://www.wiley.com/college/halliday
Problems
a unit volume of water moving from the leftmost section to the
rightmost section (a) zero, (b) positive, and (c) negative?
8 A rectangular block is pushed
face-down into three liquids, in
turn. The apparent weight W app of
the block versus depth h in the
three liquids is plotted in Fig. 14-26.
Rank the liquids according to their
weight per unit volume, greatest
first.
9 Water flows smoothly in a horizontal pipe. Figure 14-27 shows
the kinetic energy K of a water element as it moves along an x axis
that runs along the pipe. Rank the
three lettered sections of the pipe
according to the pipe radius, greatest first.
10 We have three containers with different liquids. The gauge
pressure p g versus depth h is plotted in Fig. 14-28 for the liquids.
In each container, we will fully submerge a rigid plastic bead.
Rank the plots according to the magnitude of the buoyant force
on the bead, greatest first.
2.00R
2.00R
R
(1)
3.00R
R
2.00R
(2)
2.00R
3.00R
R
(3)
R
R
3.00R
(4)
5
The teapot effect. Water
poured slowly from a teapot spout
can double back under the spout for
a considerable distance (held there
by atmospheric pressure) before
detaching and falling. In Fig. 14-23,
the four points are at the top or bottom of the water layers, inside or
outside. Rank those four points according to the gauge pressure in the water there, most positive first.
6 Figure 14-24 shows three identical open-top containers filled to
the brim with water; toy ducks float in two of them. Rank the containers and contents according to their weight, greatest first.
Figure 14-24 Question 6.
(a)
(b)
(c)
Figure 14-25 Question 7.
Figure 14-26 Question 8.
W app
h
a
b
c
406
CHAPTE R 14 FLU I DS
Water
flow
d
c
b
a
Spout
Figure 14-23 Question 5.
K
x
A
B
C
Figure 14-27 Question 9.
p g
h
a b
c
Figure 14-28 Question 10.
Module 14-1 Fluids, Density, and Pressure
•1
A fish maintains its depth in fresh water by adjusting the
air content of porous bone or air sacs to make its average density
the same as that of the water. Suppose that with its air sacs collapsed, a fish has a density of 1.08 g/cm
3
. To what fraction of its expanded body volume must the fish inflate the air sacs to reduce its
density to that of water?
•2 A partially evacuated airtight container has a tight-fitting lid
of surface area 77 m
2
and negligible mass. If the force required to
remove the lid is 480 N and the atmospheric pressure is 1.0 ϫ 10
5
Pa, what is the internal air pressure?
•3
Find the pressure increase in the fluid in a syringe when a
nurse applies a force of 42 N to the syringe’s circular piston, which
has a radius of 1.1 cm.
SSM
ILW
•4 Three liquids that will not mix are poured into a cylindrical container. The volumes and densities of the liquids are 0.50 L, 2.6 g/cm
3
;
0.25 L, 1.0 g/cm
3
; and 0.40 L, 0.80 g/cm
3
. What is the force on the
bottom of the container due to these liquids? One liter ϭ 1 L ϭ
1000 cm
3
. (Ignore the contribution due to the atmosphere.)
•5
An office window has dimensions 3.4 m by 2.1 m. As a
result of the passage of a storm, the outside air pressure drops to
0.96 atm, but inside the pressure is held at 1.0 atm. What net force
pushes out on the window?
•6 You inflate the front tires on your car to 28 psi. Later, you measure
your blood pressure, obtaining a reading of 120/80, the readings being
in mm Hg. In metric countries (which is to say, most of the world), these
pressures are customarily reported in kilopascals (kPa). In kilopascals,
what are (a) your tire pressure and (b) your blood pressure?
SSM
7 Figure 14-25 shows four arrangements of pipes through which
Tutoring problem available (at instructor’s discretion) in WileyPLUS and WebAssign
SSM Worked-out solution available in Student Solutions Manual
• – ••• Number of dots indicates level of problem difficulty
Additional information available in The Flying Circus of Physics and at flyingcircusofphysics.com
WWW Worked-out solution is at
ILW Interactive solution is at
http://www.wiley.com/college/halliday
Problems