States of Matter
Section 1:
Section 2:
Section 3:
Section 4:
Properties of Fluids
Forces Within Liquids
Fluids at Rest and in Motion
Solids
• Section 1: Fluids flow, have no definite shape, and
include liquids, gases, and plasmas.
• Section 2: Cohesive forces occur between the particles of
a substance, while adhesive forces occur between
particles of different substances.
• Section 3: Hydraulic lifts, floating objects, and carburetors
rely on the forces exerted by fluids.
• Section 4: Solids usually expand when heated.
Essential Questions
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What is a fluid?
What are the relationships among the pressure, volume,
and temperature of a gas?
What is the ideal gas law?
What is plasma?
What is surface tension?
What is capillary action?
How do clouds form?
Copyright © McGraw-Hill Education
States of Matter
Essential Questions continued
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What is Pascal’s principle?
How does Archimedes’ principle apply to buoyancy?
What is the role of Bernoulli’s principle in airflows?
How do a solid’s properties relate to that solid’s structure?
Why do solids expand and contract when the temperature changes?
Why is thermal expansion important?
Copyright © McGraw-Hill Education
States of Matter
Vocabulary
Review
New continued
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linear relationship
net force
pressure
cohesive force
New
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fluid
pressure
pascal
combined gas law
ideal gas law
thermal expansion
plasma
Copyright © McGraw-Hill Education
cohesive forces
adhesive forces
Pascal’s principle
buoyant force
Archimedes’ principle
Bernoulli’s principle
streamlines
crystal lattice
amorphous solid
coefficient of linear expansion
coefficient of volume expansion
States of Matter
As you watch…
•
Make a table of the examples shown and list the state of matter for each.
Copyright © McGraw-Hill Education
States of Matter
Follow Up
Create your own game show questions to review information from this chapter.
Some concepts you could include are
• Properties of fluids
• Pressure
• The gas laws
• Cohesive and adhesive force
• Pascal’s principle
• Buoyancy and Archimedes’ principle
• Bernoulli’s principle
• Thermal expansion
• Properties of solids
Copyright © McGraw-Hill Education
States of Matter
Essential Questions
•
•
•
•
What is a fluid?
What are the relationships among the pressure, volume, and temperature of a
gas?
What is the ideal gas law?
What is plasma?
Copyright © McGraw-Hill Education
Properties of Fluids
Vocabulary
Review
New
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linear relationship
Copyright © McGraw-Hill Education
fluid
pressure
pascal
combined gas law
ideal gas law
thermal expansion
plasma
Properties of Fluids
Liquids and Gases
• The ice cube has a
certain mass and
shape, and neither
of these quantities
depends on the size
or shape of the glass.
• If you boiled the
water, the resulting
gas (water vapor)
would flow and
expand to fill the
room but would not
have any definite
surface.
• If the ice melts, the
water flows to take
the shape of its
container and forms
a definite, flat, upper
surface.
•
Copyright © McGraw-Hill Education
Both liquids and gases are fluids,
which are materials that flow and
have no definite shape of their own.
Properties of Fluids
Pressure
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Pressure (P) is the perpendicular component of
a force on a surface divided by the area of the
surface.
Pressure is a scalar quantity.
In the SI system, the unit of pressure is the
pascal (Pa), which is 1 N/m2.
Since pressure is force exerted over a surface,
anything that exerts pressure is capable of
producing change and doing work.
Pressure
F
P 
A
Fg = 405 N
P = 210 kPa
Copyright © McGraw-Hill Education
Properties of Fluids
Pressure
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•
•
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An ideal gas is a gas whose particles take
up no space and have no intermolecular
attractive forces.
The pressure exerted by a gas can be
understood by applying the kineticmolecular theory of gases, which explains
the properties of an ideal gas.
According to this theory, the particles in a
gas are in random motion at high speed and
undergoing elastic collisions with each
other.
When a gas particle hits a container’s
surface, it rebounds, which changes its
momentum. The impulses exerted by many
of these collisions result in gas pressure on
the surface.
Copyright © McGraw-Hill Education
Properties of Fluids
Pressure
Use with Example Problem 1.
Problem
How does the average pressure of an
elephant standing on the ground compare
to that exerted by a person standing on
the ground? The person weighs 640 N.
Each shoe has an area of about 0.016 m2
in contact with the floor. The elephant
weighs 4.13×104 N and has four feet,
each with an area of about 0.14 m2 in
contact with the ground.
Response
SKETCH AND ANALYZE THE PROBLEM
• List the knowns and unknowns.
KNOWN
Fg, p = 640 N
Fg, e = 4.13×104 N
UNKNOWN
Pp = ?
Ap = 2(0.016 m2) Ae = 4(0.14 m2)
Pe =?
SOLVE FOR THE UNKNOWN
• Find the average pressures for each, using
P = F/A.
F
640 N
4
Pp  g, p 

2.0

10
Pa
2
Ap
2 0.016 m

Pe 
•
Fg, e
Ae

4.1310 4 N
4


7.4

10
Pa
2
4 0.14 m


Though the elephant’s weight is almost 65 times
that of the person, the pressure exerted by the
elephant on the ground is not even four times
greater than the pressure exerted by the
person’s soles.
EVALUATE THE ANSWER
• Pressure is in pascals, so the units are correct.
Copyright © McGraw-Hill Education
Properties of Fluids
The Gas Laws
•
•
As scientists first studied gases and
pressure, they began to notice some
interesting relationships.
Boyle’s law states that for a fixed sample of
gas at constant temperature, the volume of
the gas varies inversely with the pressure.
Boyle’s Law
•
PV
1 1  P2V2
Charles’s law states that, under constant
pressure, the volume of a sample of gas
varies directly with its Kelvin temperature.
Charles’s Law
Copyright © McGraw-Hill Education
V1 V2

T1 T2
Properties of Fluids
The Gas Laws
•
Combining Boyle’s law and Charles’s law relates the pressure, temperature, and
volume of a fixed amount of ideal gas, which leads to the equation called the
combined gas law.
Combined Gas Law
Copyright © McGraw-Hill Education
PV
PV
1 1
 2 2  constant
T1
T2
Properties of Fluids
The Gas Laws
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If the volume and temperature are held
constant, and the number of particles (N)
increases, the number of collisions that the
particles make with the container will increase,
thereby increasing the pressure.
Thus, the constant in the combined gas law
equation is proportional to N.
Instead of using N, scientists often use a unit called a mole (represented
in equations by n). One mole represents 6.022×1023 particles.
Therefore, the ideal gas law states that, for an ideal gas, the pressure
times the volume is equal to the number of moles multiplied by the
constant R (8.31 Pa·m3/(mol·K)) and the Kelvin temperature.
Ideal Gas Law
Copyright © McGraw-Hill Education
PV  nRT
Properties of Fluids
The Gas Laws
Use with Example Problem 2.
Problem
An oxygen storage bottle used by a
medical patient with poor breathing has
a volume of 4.0 L and contains gas at a
pressure of 1.3×107 Pa at 300.0 K. The
bottle releases oxygen for the patient to
breathe at atmospheric pressure. What
is the volume of oxygen that is delivered
to the patient at atmospheric pressure?
How many moles of oxygen are in the
bottle?
Response
SKETCH AND ANALYZE THE PROBLEM
• Sketch the situation.
• List the knowns and unknowns.
Copyright © McGraw-Hill Education
In Bottle
What Patient Breathes
P2, V2,
T, n
P1, V1,
T, n
KNOWN
T= 300.0 K
V1 = 4.0 L
UNKNOWN
P1 = 1.3×107 Pa
P2 = 1.013×105 Pa
V2 = ?
n=?
SOLVE FOR THE UNKNOWN
• Use Boyle’s law to find the volume.
PV
1 1  P2V2


7
1.3

10
Pa 4.0 L
PV
1 1
V2 

 520 L
P2
1.013105 Pa
Properties of Fluids
In Bottle
What Patient Breathes
The Gas Laws
Use with Example Problem 2.
P2, V2,
T, n
P1, V1,
T, n
Problem
An oxygen storage bottle used by a
medical patient with poor breathing has
a volume of 4.0 L and contains gas at a
pressure of 1.3×107 Pa at 300.0 K. The
bottle releases oxygen for the patient to
breathe at atmospheric pressure. What
is the volume of oxygen that is delivered
to the patient at atmospheric pressure?
How many moles of oxygen are in the
bottle?
Response
SKETCH AND ANALYZE THE PROBLEM
• Sketch the situation.
• List the knowns and unknowns.
Copyright © McGraw-Hill Education
KNOWN
T= 300.0 K
V1 = 4.0 L
UNKNOWN
P1 = 1.3×107 Pa
P2 = 1.013×105 Pa
V2 = 520 L
n=?
SOLVE FOR THE UNKNOWN
• Use the ideal gas law to find the
number of moles.
PV  nRT



1.3107 Pa 4.010 3 m3
PV
n 

 21 mol
m3 300.0 K
RT
8.31 Pa
molK


EVALUATE THE ANSWER
• At STP, the volume of 1 mole of ideal gas is
22.4 L. 21 moles in 520 L (24.8 L/mole) is
reasonable for conditions near STP.
Properties of Fluids
Thermal Expansion
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When heated, all forms of matter—solids, liquids, and gases—generally
become less dense and expand to fill more space. This property is known
as thermal expansion.
This thermal expansion occurs in most liquids. When a liquid is heated,
particle motion causes it to expand in the same way that particles in a solid
are pushed apart, causing the liquid to expand.
With an equal change in temperature, liquids expand considerably more
than solids, but not as much as gases.
T increases
Copyright © McGraw-Hill Education
Properties of Fluids
Thermal Expansion
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However, when water is heated from 0°C to
4°C, instead of expanding, it contracts as
the forces between particles increase and
the ice crystals collapse.
These forces between water molecules are
strong, and the crystals that make up ice
have a very open structure.
As ice melts, it still contains some tiny
crystals. These remaining crystals melt,
and the volume of the water decreases until
the temperature reaches 4°C.
However, once the temperature of water
moves above 4°C, its volume increases
because of greater molecular motion.
The practical result is that water is most
dense at 4°C and ice floats.
Copyright © McGraw-Hill Education
Properties of Fluids
Plasma
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If you keep increasing the temperature of a gas, the collisions between the
particles become violent enough to tear the electrons off of the atoms, thereby
producing positively charged ions.
The gaslike state of negatively charged electrons and positively charged ions
is called plasma.
Plasma is considered to be another fluid state of matter.
Plasma can conduct electricity.
Most of the matter in the universe is plasma.
• Stars consist mostly of plasma at extremely high temperatures.
• Much of the matter between stars and galaxies consists of energetic
hydrogen that has no electrons. This hydrogen is in the plasma state.
• Lightning bolts are in the plasma state.
• Neon signs, fluorescent bulbs, and sodium vapor lamps all contain
glowing plasma.
Copyright © McGraw-Hill Education
Properties of Fluids
Review
Essential Questions
•
•
•
•
What is a fluid?
What are the relationships among the pressure, volume, and temperature of a
gas?
What is the ideal gas law?
What is plasma?
Vocabulary
•
•
•
fluid
pressure
pascal
Copyright © McGraw-Hill Education
•
•
combined gas law
ideal gas law
•
•
thermal expansion
plasma
Properties of Fluids
Essential Questions
•
•
•
What is surface tension?
What is capillary action?
How do clouds form?
Copyright © McGraw-Hill Education
Forces Within Liquids
Vocabulary
Review
New
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net force
Copyright © McGraw-Hill Education
cohesive forces
adhesive forces
Forces Within Liquids
Cohesive Forces
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In real fluids, particles exert electromagnetic forces of attraction, called
cohesive forces, on each other.
Beneath the surface of the liquid, each particle of the liquid is attracted
equally in all directions by neighboring particles and to the particles of the
wall of the container.
At the surface, however, the particles are attracted
downward and to the sides, but not upward. There
is a net downward force on the top layers which
causes the surface layer to be slightly
compressed.
The result is surface tension, which is the
tendency of the surface of a liquid to contract to
the smallest possible area.
The higher a liquid’s surface tension, the more
resistant the liquid is to having its surface broken.
Copyright © McGraw-Hill Education
Forces Within Liquids
Cohesive Forces
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In nonideal fluids, the cohesive forces and
collisions between fluid molecules cause internal
friction that slows the fluid flow and dissipates
mechanical energy.
The measure of this internal friction is called the
viscosity of the liquid.
Water is not very viscous, but motor oil is very
viscous.
As a result of its viscosity, motor oil flows slowly
over the parts of an engine to coat the metal and
reduce rubbing.
Copyright © McGraw-Hill Education
Forces Within Liquids
Adhesive Forces
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Adhesive forces are electromagnetic
attractive forces that act between particles of
different substances.
When a glass tube is placed in a beaker of
water, water climbs the outside of the tube.
The adhesive forces between the glass
molecules and water molecules are greater
than the cohesive forces between the water
molecules.
In contrast, the cohesive forces between
mercury molecules are greater than the
adhesive forces between the mercury and
glass molecules, so the liquid does not climb
the tube. Instead, the center of the mercury’s
surface is depressed.
Copyright © McGraw-Hill Education
Forces Within Liquids
Adhesive Forces
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The water rises inside the tube for the same
reason. This phenomenon is called capillary
action.
If the radius of the tube increases, the volume
and the weight of the water will increase
proportionally faster than the surface area of
the tube.
Thus, water is lifted higher in a narrow tube
than in a wider one.
Capillary action causes molten wax to rise in a
candle’s wick and water to move up through
the soil and into the roots of plants.
Copyright © McGraw-Hill Education
Forces Within Liquids
Evaporation and Condensation
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If a fast-moving particle can break through the surface layer, it will escape from
the liquid. This escape of particles is called evaporation.
Particles of liquid that have evaporated into the air can also return to the liquid
phase if the kinetic energy or temperature decreases. The process is called
condensation.
The air above any body of water contains
evaporated water vapor, which is water in
the form of gas.
If the temperature is reduced, the water
vapor condenses around tiny dust particles
in the air and produces droplets only 0.01 mm
in diameter. A cloud of these droplets close to
the ground is called fog. Fog often forms when
moist air is chilled by the cold ground.
Copyright © McGraw-Hill Education
Forces Within Liquids
Review
Essential Questions
•
•
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What is surface tension?
What is capillary action?
How do clouds form?
Vocabulary
•
cohesive forces
Copyright © McGraw-Hill Education
•
adhesive forces
Forces Within Liquids
Essential Questions
•
•
•
What is Pascal’s principle?
How does Archimedes’ principle apply to buoyancy?
What is the role of Bernoulli’s principle in airflows?
Copyright © McGraw-Hill Education
Fluids at Rest and in Motion
Vocabulary
Review
New
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pressure
Copyright © McGraw-Hill Education
Pascal’s principle
buoyant force
Archimedes’ principle
Bernoulli’s principle
streamlines
Fluids at Rest and in Motion
Fluids at Rest
•
Pascal’s principle states that any change in pressure applied at any point
on a confined fluid is transferred undiminished throughout the fluid.
Go to your ConnectED resources to play Animation: Pascal’s Principle.
Copyright © McGraw-Hill Education
Fluids at Rest and in Motion
Swimming Under Pressure
Go to your ConnectED resources to play Animation: Buoyancy.
Copyright © McGraw-Hill Education
Fluids at Rest and in Motion
Swimming Under Pressure
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The increase in pressure with increasing depth creates an upward force called
the buoyant force.
Archimedes’ principle states that an object immersed in a fluid has an upward
force on it that is equal to the weight of the fluid displaced by the object.
The force does not depend on the weight of the object, only on the weight of the
displaced fluid.
Buoyant Force
•
Fbuoyant   fluidVg
The difference between the buoyant force and the object’s weight determines
whether an object sinks or floats.
Copyright © McGraw-Hill Education
Fluids at Rest and in Motion
Swimming Under Pressure
Fbuoyant
●
Fg, A;
Use with Example Problem 3.
Problem A
A child folds a piece of aluminum foil that
has a mass of 0.012 kg into a boat that
floats on the water. What volume of
water does the foil boat displace?
Fbuoyant  Fg, Al
Response
SKETCH AND ANALYZE THE PROBLEM
• Sketch the situation.
• List the knowns and unknowns.
KNOWN
UNKNOWN
mAl = 0.012 kg
Vwater = ?
ρwater = 1.0×103 g/cm3
Copyright © McGraw-Hill Education
SOLVE FOR THE UNKNOWN
• Because the boat floats, the buoyant
force is equal to the weight of the
boat.
 waterVwater g  mAlg
Vwater 
mAl
 water

0.012 kg
1.0103 kg/m3
 1.210 5 m3
EVALUATE THE ANSWER
• For a 12-g aluminum foil boat, a
displacement of 12 mL of water is
reasonable.
Fluids at Rest and in Motion
Swimming Under Pressure
●
Fg, Al
Use with Example Problem 3.
Problem B
The child crumples the same boat
into a tight ball that sinks in the
water. How much volume does the
foil displace, assuming that no air
is trapped? What is the apparent
weight of the foil ball underwater?
Response
Fbuoyant
SOLVE FOR THE UNKNOWN
• Calculate the volume of the aluminum ball.
VAl 
•
mAl
 Al

0.012 kg
 4.410 6 m3
3
3
2.7010 kg/m
This is the volume of water displaced by the
submerged ball. The apparent weight is its weight
minus the buoyant force on the submerged ball.
SKETCH AND ANALYZE THE PROBLEM Fapparent  Fg, Al  Fbuoyant  mAlg   waterVwater g
• Sketch the situation.
N
 0.012 kg 9.8 kg
• List the knowns and unknowns.
KNOWN
mAl = 0.012 kg
ρAl = 2.7×103 g/cm3
ρwater = 1.0×103 g/cm3
Copyright © McGraw-Hill Education


 1.0103

4.410
kg
m3
6

m3 9.8
UNKNOWN
 0.074 N
VAl = ?
Fapparent = ? EVALUATE THE ANSWER
• The apparent weight is less than the actual
weight, as expected.
N
kg

Fluids at Rest and in Motion
Bernoulli’s Principle
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•
•
•
Bernoulli’s principle states that as the velocity of a fluid increases, the
pressure exerted by that fluid decreases.
This principle is a statement of work and energy conservation as applied
to fluids.
If a certain mass of smoothly flowing ideal fluid enters one end of the
pipe, then an equal mass must come out the other end.
Suppose the pipe’s cross
section becomes narrower.
To keep the same mass of
fluid moving through the
narrow section in a fixed
amount of time, the velocity
of the fluid must increase.
Copyright © McGraw-Hill Education
Fluids at Rest and in Motion
Bernoulli’s Principle
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•
•
•
As the fluid’s velocity increases, so does its kinetic energy. This means
that net work has been done on the swifter fluid.
The work is proportional to the force on the fluid, which, in turn, depends
on the pressure.
If the net work is positive, the pressure at the input end of the section,
where the velocity is lower, must be larger than the pressure at the
output end where the velocity is higher.
Applications of Bernoulli’s principle:
• paint sprayers
• perfume bottles
• gasoline engine’s carburetor
Copyright © McGraw-Hill Education
Fluids at Rest and in Motion
Bernoulli’s Principle
•
•
•
Automobile and aircraft manufacturers
spend a great deal of time and money
testing new designs in wind tunnels to
ensure the greatest efficiency of
movement through air.
The flow of fluids around objects is
represented by streamlines.
Objects require less energy to move
through a smooth streamlined flow.
Copyright © McGraw-Hill Education
Fluids at Rest and in Motion
Review
Essential Questions
•
•
•
What is Pascal’s principle?
How does Archimedes’ principle apply to buoyancy?
What is the role of Bernoulli’s principle in airflows?
Vocabulary
•
•
Pascal’s principle
buoyant force
Copyright © McGraw-Hill Education
•
•
Archimedes’ principle
Bernoulli’s principle
•
streamlines
Fluids at Rest and in Motion