Name
Date
Solids, Liquids, and Gases
Section 2 Properties of Fluids
Preview Write four questions you have after reading this section.
1. Accept all reasonable responses. What is Archimedes’
principle?
2. What is Pascal’s principle?
3. What is Bernoulli’s principle?
4. How are these three principles applied in real life?
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Review
Vocabulary Define the term density.
density
mass per unit volume of a material
New
Vocabulary Use each term in a sentence that reflects the term’s scientific
meaning.
buoyancy
Accept all reasonable responses. Sample: It feels like the water
lifts me when I am floating.
pressure
Sample: The pascal is one Newton per square meter and
measures pressure.
viscosity
Sample: Syrup’s viscosity is high when it is cold and low when
it is hot.
Academic
Vocabulary Use a dictionary to define the term displace.
displace
to move physically out of position; replace
Solids, Liquids, and Gases
175
Name
Date
Section 2 Properties of Fluids
Archimedes’
Principle and
Buoyancy
(continued)
Evaluate the buoyant force on a block of iron and a block of plastic
foam. Each block has the same volume. Make sketches that show the
forces acting on each block, and whether each block sinks or floats.
I found this information
on page
.
Student sketch should show
buoyant force pushing up and
weight pushing down. Iron
sinks to the bottom, plastic
floats.
SE, pp. 441–442
RE, pp. 256–257
Organize the physical properties of two identical pieces of foil
formed into different shapes. One piece of foil is crumpled tightly
into a ball. The other is folded into a box that is open on top. What
happens when both pieces are dropped into a container of water?
Use the terms below to complete the Venn diagram.
floats
foil and air displace water
higher density
less volume displaced
lower density
•
•
•
•
•
Box
Ball
less volume
displaced
only foil
displaces
water
higher
density
sinks
Pascal’s
Principle and
Pressure
I found this information
on page
.
SE, pp. 442–443
RE, p. 257
Both
mass
weight
more volume
displaced
foil & air
displace water
lower
density
floats
Summarize Pascal’s principle in your own words. Include two
examples of objects that work because of Pascal’s principle, other
than those given in your book.
Answers may vary. Pressure applied to a fluid is transmitted or
sent throughout the fluid.
Examples
1. braking system in an automobile
2. squeezing lotion out of a bottle
176
mass
more volume displaced
only foil displaces water
sinks
weight
Solids, Liquids, and Gases
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
•
•
•
•
•
Name
Date
Section 2 Properties of Fluids
Bernoulli’s
Principle
(continued)
Explain how Bernoulli’s principle makes the hose-end sprayer
operate.
I found this information
on page
.
Water moves
through the sprayer
at high speed.
SE, p. 445
RE, p. 258
The fast-moving water creates a
low-pressure area, pulling chemicals
up the tube.
The water-chemical
mixture sprays out of
the tip.
Strawlike
tube
Concentrated
chemical solution
Sample answer: The water from the hose flows at a high rate over
the end of the tube in the concentrate. The high flow rate reduces
the pressure over the small tube pulling concentrate from the
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
container.
Viscosity
I found this information
on page
.
SE, p. 446
RE, p. 258
Analyze the relationship between viscosity and temperature that
is suggested by the saying “as slow as molasses in January”.
Accept all reasonable responses. Viscosity is fluid’s resistance to
flow. When a container is tilted for flow to begin, flowing particles
transfer energy to stationary particles to “pull” them into the flow.
When less energy is available at a lower temperature (as in the
winter month of January), there is less transfer and less “pull”
into the flow. At higher temperatures, liquids flow more readily,
because more energy is transferred.
CONNECT IT
Use Bernoulli’s principle to explain how a hurricane wind might
lift a roof from a house.
Fast-moving winds occur in low pressure. Stable winds (air) inside the house push the
roof up into the low pressure region of the storm above the house.
Solids, Liquids, and Gases
177