Applied Technology
Level 1
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1
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2 • Applied Technology
1
INTRODUCTION
Hi! Welcome to Level 1 of Applied Technology.
My name is EdWIN. I will be your guide
through this course. This is the first of six levels
of Applied Technology. You may not need to
complete all six levels. You can be sure that I
will be here to help you with any level you need
to complete. Watch for me to pop up along the
way with a tip or suggestion about what you are
studying.
Hi, I’m EdWIN!
Applied Technolog y will help you to
understand the basics about heat, fluids,
electricity, and mechanics. Don’t worry. I am
going to make everything as clear as I can. We
will start with the basics – some things you may
already know. You can move at your own pace.
We will work together.
In this level, you will learn some basics about
science and technology. This will help you get
ready to learn more difficult material in other
levels of Applied Technology.
Now that I have told you a little about this
course, are you ready to go? OK, then let’s begin!
Applied Technology • 3
1
LEARNING OBJECTIVES
In this level you will:
• define the word technology.
• discuss basic principles and laws of nature.
• examine basic forms of matter.
• define energy.
• examine principles of heat.
• examine the concept of pressurized liquids
and gases.
• define machine.
• examine the inclined plane.
• examine the lever.
4 • Applied Technology
OUTLINE
1
LESSON 1
Applied Technology: The Basics
LESSON 2
Principles: Energy and Heat
LESSON 3
Mechanics: An Overview
LESSON 4
Mechanics: The Inclined Plane
LESSON 5
Mechanics: The Lever
LESSON 6
Posttest
REFERENCE
Glossary
Applied Technology • 5
LESSON 1
1
APPLIED TECHNOLOGY:
THE BASICS
In this lesson, we will define technology and
other words that are sometimes used with it. The
purpose of the lesson is to help you understand
more about basic science principles. We will look
at words that deal with heat, fluids, electricity,
and mechanics. Do not let these words make
you nervous. You may find that you already
know more about them than you think. I will
try to keep things as simple as possible. Let’s
start by defining the word technology.
Technology
Some tools are for
work and pleasure.
6 • Applied Technology
From the beginning of time, people quickly
learned that in order to survive, they had to do
work. This work was not always pleasant. They
had to find ways to make it easier. They began
to make tools. Spears, knives, and hunting traps
are examples of early tools. People have
continued to find ways to make work easier.
Today, we have many tools that help us in work
and pleasure. Technology is simply the use of tools
or methods to do work more easily.
1
LESSON 1
The basic tools we will be talking about in
Applied Technology fall into the following topics:
• Thermodynamics (the influence and use of
heat)
• Fluid Dynamics (the use of liquids and
pressure)
• Mechanics (the study of basic machine types)
• Electricity (practical applications of electrical
power)
We will study more about each one of these
topics in future levels. However, it is important
that you have an idea of what they mean. We
will talk about several basic science terms in this
level. As you understand the terms, you should
try to decide how they apply to these four topics.
Applied Technology • 7
1
LESSON 1
Principles/Laws of Nature
A principle, as used in this course, means a
law or fact of nature. There are basic laws or
principles. For example, there are laws of gravity.
We know that if you hold a rock in your hand
and let it go, it will not go up. It will not move
sideways, nor stay where it is. It will go down!
This fact has been proven. It is a law or principle
of science.
The law of inertia states that an object at rest
tends to stay “at rest.” An object in motion tends
to stay “in motion.” Think about a large rock
sitting on level ground. It will take great effort
to move the rock when it is at rest. Now, picture
the same big rock tumbling down a hill. It will
take great effort to stop the rock because it is in
motion.
We will talk about these and other principles
in this course. For now, it is important that you
know what I mean by the word, principle.
8 • Applied Technology
LESSON 1
1
Matter and Molecules
Everything in our world is made of matter.
Matter is all the material that has mass and
occupies space. Matter is grouped into different
forms. These forms include solids, liquids, and
gases. Matter is made of molecules, and
molecules are made of atoms. Don’t worry. I am
not going to get too technical.
Different types of matter have different
properties. Some of the properties are weight,
volume, mass, and density. Let’s define these
characteristics of matter.
Weight
Weight is an amount of heaviness. Most of us
have an idea of what weight means. For example,
we know our body weight. Also, when we lift
an object, we notice the object’s weight. Weight
is a measurement of gravity’s pull on forms of
matter.
Applied Technology • 9
LESSON 1
1
Volume
Volume is how we measure space. We use
volume to measure the amount of space in a
box or amount of space in a room. The amount
of space in a water tower, which could be a
cylinder or a sphere, is also measured as volume.
The total amount of air space in a house is very
important in determining the right equipment
for proper heating and air conditioning. Volume
is also used to measure the amount of space
occupied by a substance such as a liquid or a
solid. As an example, two cubic feet of water
will occupy two cubic feet of space.
Volume is measured in cubic inches, cubic
feet, cubic yards, cubic meters, etc. One cubic
inch is a measure one inch in length, one inch
in width, and one inch in height. (See Figure
1.) One cubic foot is an area that measures one
foot in length, one foot in width, and one foot
in height. (See Figure 2.)
t
1
foo
1 inch
1
1 inch
Figure 1
10 • Applied Technology
1 foot
h
inc
1 foot
Figure 2
1
LESSON 1
The shape of a space determines how the
volume is measured. The volume of a box is
found by multiplying the length by the width
by the height.
Liquids are commonly measured by
containers with markings. These marks show
levels such as pints, quarts, gallons, or liters. The
measuring cup used in cooking is a good example
of a measuring container.
Volume is not a measure of weight. Weight
is determined by the substance. We will discuss
volume of other shapes such as cylinders and
spheres in later levels.
Applied Technology • 11
LESSON 1
1
Thinking Activity
How many cubic inches are in a cubic foot?
s
e
ch
n
12 inches
i
2
1
1 in
12 inches
Answer: 1,728 cubic inches in 1 cubic foot
12 inches × 12 inches × 12 inches = 1,728 cubic inches
12 • Applied Technology
LESSON 1
1
Mass
The mass of an object is a measure of the
amount of material it contains. Do not get mass
confused with weight. Weight, if you recall,
depends on gravity’s pull on the object. An
astronaut weighs more on earth than in space
because the pull of gravity is weaker in space.
However, the astronaut’s mass stays the same.
The makeup of the astronaut basically does not
change.
Density
Density is another property used to describe
matter. It compares mass to volume. Density tells
how tightly packed a substance might be.
Consider that we have a fixed volume of
material, which means a fixed amount of space.
Then the more dense the substance in that space,
the heavier the material must be in the container.
Do you remember that earlier I said matter is
made of molecules? The closer the molecules are,
the more dense a substance is. Density is a ratio
of mass to volume.
Applied Technology • 13
LESSON 1
1
Thinking Activity
<
Suppose you have a gallon of water and a gallon of molasses. Which
one do you think is more dense?
Answer: Molasses is denser than water. In containers of the same
size (meaning the volume or amount of space is the same),
the molasses would be heavier. The compactness of molecules
in molasses causes it to be denser.
Thinking Activity
Assume you have two blocks that are the same size and shape.
One is made of lead. The other is made of copper. Which one
would be heavier? Why do you think so?
<
Answer: The lead is heavier because the molecules in it are much
more densely packed than those in copper.
Let’s think about this again. Take the same block of lead and a
block of balsa wood. Drop them in a bucket of water. What
happens?
Answer: The lead block sinks to the bottom. This is because the
molecules in lead are more densely packed than molecules
in water. The weight and density of the lead is such that it
pushes the water aside and sinks. On the other hand, the
density of the wood is less than that of the water. Therefore,
the water supports the wood, and it floats.
14 • Applied Technology
LESSON 1
1
Thinking Activity
<
Suppose you gently place an egg in a glass of water. Will the egg
sink or float?
Answer: Depending on the temperature of the water and the egg, it
will most likely sink. The egg is denser than water.
Suppose you remove the egg. Pour about ten tablespoons of salt
in the water and stir until it mixes with the water. What will happen
when you place the egg in the water?
Answer: Salt water is denser than the egg. This time the egg should
float.
Now that we have a basic understanding of
these properties, let’s look at the three forms of
matter. Earlier I said all matter is either a solid,
liquid, or gas. These forms are easy to recognize.
Solids
Solids retain their shape and volume. A block
of wood is a solid. Solids do not usually mix
with other solids.
Applied Technology • 15
LESSON 1
1
Liquids
Liquids retain volume but take the shape of
the container. You can pour a liquid from one
container into another. The amount stays the
same, but the shape of the liquid changes.
Liquids may be mixed with other liquids.
Gases
Gases take up both the volume and shape of
a container. A gas released into a room will spread
throughout the entire room. Gases change shape
and volume. This form of matter may be
invisible and is easily mixed with other gases.
16 • Applied Technology
LESSON 1
P
1
ume
erfStars
of
There are many different types of solids,
liquids, and gases. Their type depends on their
chemical makeup. In this course we will not
discuss the makeup of substances but look at
how they sometimes change form.
Molecules in solids are
packed tightly together in
fixed positions. They pull
hard on each other,
making it difficult for the
solid to change shape.
In liquids, the molecules
are close to each other
and pull toward each
other. They are free to
move around and
change places, so
liquids can change
shape.
Molecules in gases are
very widely spaced, so
gases can be squeezed.
The force holding these
molecules together is
very weak, so gases are
easily scattered.
Figure 3
Applied Technology • 17
LESSON 1
1
Thinking Activity
<
Suppose you set a glass on a level surface. Fill the glass with water
all the way to the brim of the glass. What if you gently slide a coin
into the glass. Will it overflow?
Answer: If you look carefully, you may see the water bulge over the
brim. You may be able to slide several coins into the glass
before it spills. This is because molecules in water pull
toward each other. They will hold the water together as
long as they can. Water forms drops because its molecules
pull together.
Solids to Liquids
In some cases, matter can move between
types. Let’s see how some matter changes.
Metals are normally in a solid state. However,
when heated, the molecules in metal increase
their movement. When the temperature is raised
high enough, the metal becomes molten. It is
now in a liquid state. This can be used to our
advantage. Metal can then be poured or cast into
shapes that we want. When it cools, it becomes
a solid again. The temperature at which a solid
becomes a liquid varies between types of metals.
For example, iron becomes liquid at a certain
temperature. Gold becomes liquid at a different
temperature.
18 • Applied Technology
LESSON 1
1
Understanding these principles has been
helpful to us in another way. As you recall, solids
do not mix with other solids. However, liquids
may mix. Different metals have different
qualities. By combining some of these qualities,
we can make stronger and lighter metals that
last longer. We can heat metals to their liquid
state. Then, we can combine the metals. When
cooled, we have an improved product. These
metals are called alloys. Steel is our most
common alloy.
Evaporation
When water is heated, the molecules react to
the heat. They increase their movement. Steam
begins to come from the water. The steam is
taken into the air or gas around the water. This
is an example of matter moving from a liquid
form to a gas form. This process is called
evaporation. The molecules have not been
destroyed. They have only been changed to
another form of matter. If the water continues
to heat, all of the liquid will turn into gas.
Applied Technology • 19
LESSON 1
1
Condensation
In condensation, gas changes into a liquid
form. For example, think about a warm breeze
blowing on a glass of ice water. Beads of liquid
begin to form on the outside of the glass. This
occurs because the air contains many free
moving molecules. As the air comes in contact
with the cold glass, the molecules begin to slow
down their movement. When their movement
becomes slow enough, water molecules in the
air condense into liquid water.
Evaporation and condensation occur around
us every day. Understanding these principles can
be helpful when designing tools or machinery.
These principles are basic to heating and
refrigeration systems. It is important to
understand that forms of matter can be changed.
20 • Applied Technology
1
LESSON 1
EXERCISE – PROPERTIES OF MATTER
Instructions:
1.
Read each description of something that happens. Then, read the
question(s) about it. Select the letter of the process that you think
has occurred.
Ken has two balloons. They both are made of the same
material and are the same size. He fills one balloon with
air. He fills the other one with a gas called helium. Both
balloons are tightly tied when filled. Right after Ken fills
the balloons, he lets go of them. The helium balloon floats
up. The one filled with air falls to the ground.
What is one reason that the balloons behave differently?
a. The air evaporated from the air-filled balloon.
b. The helium evaporated from the helium-filled balloon.
c. Molecules in the helium are more dense than molecules
in the air.
d. Molecules in the helium are less dense than molecules
in the air.
Applied Technology • 21
1
2.
LESSON 1
John drove his car to the ski slope. The temperature outside
dropped as he drove higher up the mountain. He turned
the heater on in the car, so he could stay warm. The
windshield soon became difficult for John to see through.
What principle caused the problem with the windshield?
a. evaporation
b. condensation
c. gravity
d. inertia
3.
Lani lives on an island in the Pacific. She has seen a volcano
erupt. The molten lava was red hot. It flowed down the side
of the volcano and ran into the ocean.
What form of matter is lava?
a. solid
b. liquid
c. gas
d. alloy
4.
What happens to the lava when it is cooled by the ocean
water?
a. The matter changes form.
b. It continues to flow under the ocean.
c. It turns into an alloy.
d. It does not obey the laws of gravity.
22 • Applied Technology
1
5.
LESSON 1
Jay is learning to drive a car. His learner’s manual says to
keep a safe-driving distance between his car and the car in
front of him. A good rule of thumb for normal driving
conditions is to allow one car length for every ten miles an
hour you are traveling.
What law or principle is considered in making this rule?
a. evaporation
b. condensation
c. gravity
d. inertia
Applied Technology • 23
1
LESSON 1
ANSWERS TO EXERCISE
1.
Ken has two balloons. They both are made of the same
material and are the same size. He fills one balloon with
air. He fills the other one with a gas called helium. Both
balloons are tightly tied when filled. Right after Ken fills
the balloons, he lets go of them. The helium balloon floats
up. The one filled with air falls to the ground.
What is one reason that the balloons behave differently?
Answer: d. Molecules in the helium are less dense than
molecules in the air.
2.
John drove his car to the ski slope. The temperature outside
dropped as he drove higher up the mountain. He turned
the heater on in the car, so he could stay warm. The
windshield soon became difficult for John to see through.
What principle caused the problem with the windshield?
Answer: b. condensation
24 • Applied Technology
1
3.
LESSON 1
Lani lives on an island in the Pacific. She has seen a volcano
erupt. The molten lava was red hot. It flowed down the side
of the volcano and ran into the ocean.
What form of matter is lava?
Answer: b. liquid
4.
What happens to the lava when it is cooled by the ocean
water?
Answer: a. The matter changes form.
5.
Jay is learning to drive a car. His learner’s manual says to
keep a safe-driving distance between his car and the car in
front of him. A good rule of thumb for normal driving
conditions is to allow one car length for every ten miles an
hour you are traveling.
What law or principle is considered in making this rule?
Answer: d. inertia
Applied Technology • 25
1
LESSON 1
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26 • Applied Technology
1
LESSON 2
PRINCIPLES: ENERGY AND HEAT
How are you doing? Were you familiar with
any of the basic concepts we talked about in
Lesson 1? We will continue to talk about the
principles and properties of solids, liquids, and
gases as we go through the different levels of
Applied Technology. I hope that you have a basic
understanding of the words that were
introduced.
In this lesson, we will discuss words associated
with energy and heat. We will look at their effects
or influence on applied technology. Let’s begin
by defining energy.
Applied Technology • 27
LESSON 2
1
Energy
Energy, simply stated, is the ability to do work.
The sun is the primary source of energy in our
world. The sun provides energy to support plant
and animal life. It is the key factor in developing
and supporting our natural resources.
People have found many forms of energy and
ways to use this energy in doing work. Energy
sources discovered early include fire, water, and
wind. Simple machines were invented to make
work easier. New forms of energy were developed
using steam and gasoline engines, electricity, and
atomic energy. These sources of energy have led
to the invention of more complex machines that
do even more work faster.
My grill is doing
work!
In the United States, energy is normally
measured in foot-pounds. One foot-pound is the
amount of energy required to move an object
one foot against a resistance of one pound. As
an example, to raise 10 pounds a distance of 2
feet requires 20 foot-pounds of energy.
Applied technology uses examples of multiple
energy sources and how they are used in doing
work.
28 • Applied Technology
LESSON 2
1
Heat
Heat is a common source of energy. Earlier I
said the sun and its heat is an energy source.
Other sources can create heat. As matter is
heated, the molecules within the matter begin
to move. As the heat is increased, the amount of
molecule movement also increases. This motion
is a form of energy.
Heat applied to water creates steam, which
in turn can drive machines. Electricity applied
to a lightbulb creates heat across a thin wire,
and the bulb begins to glow. As you can see,
energy does work.
MOVING MOLECULES
HEAT
HEAT
HEAT
Applied Technology • 29
LESSON 2
1
Conduction
One way that heat travels is by conduction. A
conduit is a path that eases the passage of energy
or matter from one place to another. A water
pipe is a conduit for water into your home. Metal
wires are conductors of electricity. Different
substances are also conductors of heat. The
transferring process is called conduction.
Some forms of matter are better conductors
of heat than others. Metal is a conductor of heat.
Think about a metal pot being placed on a stove.
When the energy source is turned on, heat will
move from the stove to the metal pot. At first,
the bottom of the pot will become hot. It is in
direct contact with the energy source. Since
metal is a conductor, molecules in the sides of
the pot will begin to move faster causing the
entire pot and its contents to become hot.
Contact with
heat source
Conduction of heat to pot
Figure 4
30 • Applied Technology
LESSON 2
1
Insulation
The opposite effect of conduction is
insulation. This means limiting the amount of
transfer of heat, sound, electricity, and other
energy forms. Materials that do not allow
molecules to move freely normally provide
insulation. They are used to separate conducting
bodies. Houses are insulated with materials that
slow the transfer of heat. During the winter, the
warm air is kept inside while the cold air is not
transferred from the outside. During the
summer months, the cold air is kept inside, and
the warm air remains outside. Without
insulation, the energy used for heating and air
conditioning would greatly increase.
Rubber, plastics, and Styrofoam™ are other
examples of insulators. Styrofoam is used in
coffee cups and picnic coolers. The insulation
process is the same. The contents of the
containers tend to hold their temperature longer
because of the limiting of temperature transfer
to the matter around them.
Rubber, plastics, and glass are used as
insulators to electrical current flow. Insulators
in electricity are used to limit and guide current
flow and for safety. Examples of this use are
present around your home. The electrical circuits
that provide electrical power throughout a house
are made of insulated wires.
Applied Technology • 31
LESSON 2
1
Thinking Activity
<
Close your eyes and think of items that use the principle of
insulation around the home. How many items can you think of?
Answer (partial list): oven, refrigerator, freezer, walls, ceilings, floors,
heating and air-conditioning ductwork, water heater, appliance cords,
appliance cases, TV antenna/cable wires, clothing …
Reflection
Some clothing has better insulation
characteristics than others. Other characteristics
also come into play. The clothes that you wear
may or may not be good conductors of heat.
Sometimes clothing may reflect heat. The word
reflect means to bend or throw back. When used
in Applied Technology, it refers to throwing back
heat, light, or sound.
Light waves are reflected by mirrors. You see
the reflection as the waves bounce back to you.
Light-colored objects reflect heat more than dark
objects. On a bright summer day, you will feel
cooler wearing a white shirt than a black one as
more of the heat will be reflected away. The same
is true for pavement. Light-colored concrete will
reflect more heat than black asphalt.
The turnaround of direction that occurs
when a wave bounces off a surface is called
reflection.
32 • Applied Technology
LESSON 2
1
Absorption
If a surface does not reflect, it absorbs. The
word absorb means to take in. A dry sponge will
take in or soak up liquids. We say the sponge
absorbs liquids. In our previous discussion about
shirts, the black shirt absorbed heat while the
white one reflected heat.
As we study heat, we will use the word
absorption. Absorption, in this case, is the process
of heat being taken in by an object.
Applied Technology • 33
LESSON 2
1
Friction
Friction is the creation of energy when matter
rubs against matter. This can be in the form of
solids, liquids, or gases. The rubbing action
creates heat. Friction opposes movement, and
the heat it generates will die down when
movement stops. The amount of friction is
determined by the following:
• the types of matter coming into contact
• the surface of the contact area (irregular,
coarse, or smooth)
• the amount of pressure applied to the objects
• the speed at which the objects are rubbed
In many cases, friction is the arch enemy of
machinery. The heat generated by friction
represents lost energy. People have long tried to
create a constant motion machine. This would
be a machine that would run forever on its own
energy. This would be a 100 percent efficient
machine. While great improvements have been
made, the perfect machine is still out of reach.
We have not found a way to totally eliminate
friction.
➟
Little friction is created … allowing me
to slide across the ice.
34 • Applied Technology
1
LESSON 2
The automobile engine is a good example of
how friction affects machines. The engine
contains many moving parts. The parts have
been made with very strong alloys. Where parts
come in contact with other parts, they have been
ground and polished, so the surfaces are very
smooth.
Systems are installed to constantly put
lubricants onto the surfaces that make contact.
Still, we know the engine will eventually wear
out. The cause is friction and its resulting heat
and wear. This explains why you should check
and change your oil regularly!
Friction can also be used to our advantage.
Using that same car as an example, the tires grip
the road because of friction. The tread has many
small surfaces that push against the road and
allow for good steering. Brakes are another
example of the positive use of friction. Brake
pads are forced against disks or drums mounted
on the wheels. This creates friction, a force that
causes the car to slow or stop.
You may have heard a race car driver talking
about the brakes heating up and then losing the
brakes. This occurs with intense and excessive
use of the brakes. Too much friction and too
much heat cause the brakes to fail.
Applied Technology • 35
LESSON 2
1
When you walk, friction allows you to
navigate your way. The soles of your shoes in
contact with the ground creates friction. Rubber
soles on a slightly rough surface give you
maximum stability. Try the same stroll on ice …
the friction goes down … and most of the time
you do, too!
Thinking Activity
Suppose you have two cans. Can 1 sits with the bottom firmly
against the table. Can 2 sits on a layer of marbles. What happens
if you try to spin the two cans?
Can 1
Can 2
Answer: Friction from the bottom of the can and the table will keep
Can 1 from spinning. The marbles under Can 2 will roll
when the can is turned. This will keep the base from
rubbing on the surface of the table. Rolling creates much
less friction than a solid surface moving against the table.
36 • Applied Technology
LESSON 2
1
Pressure
Pressure is the application of force. A force is a
push or a pull. Pressure can be the output force
of a machine, or it can be liquid or air/gas
pressure. The normal measure of pressure is
stated as pounds per square inch (psi). The
measure 100 psi means there are 100 pounds of
pressure being applied to each square inch of a
surface. You may be familiar with psi from
checking the air pressure in your tires. Your tires
may be inflated to 32 psi. This means they have
32 pounds of pressure on each square inch inside
the tire.
Liquid pressure is also measured in psi. Water
pressure is probably the easiest to see. Liquid
pressure is determined by the weight of the liquid
and the force being applied to the liquid. With
no other force being applied, the pressure at the
bottom of a container will increase as the height
of the liquid in the container increases. This is a
result of the increasing weight. Pressure halfway
up the container will be less than that at the
bottom because the weight is less.
Applied Technology • 37
LESSON 2
1
less pressure
more pressure
Figure 5
Let’s take a look at a common application of
liquid weight and pressure. When you open a
faucet at your home, hopefully the water does
not trickle out. It should come out with a good
deal of pressure. One method of achieving this
is through the use of very tall water towers, which
we see dotting the landscape. Thousands of
gallons of water are stored in these tanks. You
can imagine that the weight of the water creates
a tremendous force at the bottom of the tank.
This weight creates the water pressure needed
to run your household.
38 • Applied Technology
LESSON 2
1
Compression
Fluids and gases can be pressurized. An outside
force can be applied to a fluid or gas in an airtight
space. This pressure forces the molecules closer
together. This is called compression. When the
pressurized fluid or gas is released, as the molecules
expand, a much greater force is exerted than that
caused by the weight of the substance alone. Pumps
are used to pressurize liquids and gases.
This process of compressing/pressurizing
liquids and gases is the basis for many practical
applications. For example, compressed air is used
to inflate tires, spray paint, and operate power
tools. Hydraulics is the use of pressurized liquids
to exert tremendous forces in lifting, pushing,
and pulling. These applications range from
operating the power brakes and power steering
in your car to the unbelievable power of heavy
earth-moving equipment.
Thinking Activity
<
Suppose you have a watch that is guaranteed to be waterproof to a
depth of 100 feet. You take it to 200 feet. What likely happens and
why?
Answer: Your guarantee is no longer valid. The water pressure is
greater at 200 feet than at 100 feet. The seals may not be
able to hold the water out of the watch. The leaky seals
may cause the watch to malfunction.
Applied Technology • 39
1
LESSON 2
EXERCISE – PRINCIPLES OF ENERGY
Instructions:
1.
Read each question. Select the letter of the response that best
answers the question.
Mary wore a pair of thick gloves when she went snow skiing.
What principle is Mary using to keep her hands warm?
a. reflection
b. insulation
c. conduction
d. friction
2.
Dan checks the level of motor oil in his boat every weekend
before taking it out. What principle is Dan aware of and
trying to prevent?
a. reflection
b. insulation
c. conduction
d. friction
3.
What material should Josh select to use as a conductor of
an electric current?
a. plastic
b. rubber
c. paper
d. copper
40 • Applied Technology
1
4.
LESSON 2
Craig wants George to learn to scuba dive. George is afraid.
From the size of the tanks, he thinks the air will run out
while he is under the water. What principle should Craig
try to explain to convince George to dive with him?
a. gravity
b. compressed air
c. lack of friction
d. absorption
5.
Cain must lift a wooden crate 3 feet to place it on the loading
dock. The crate weighs 15 pounds. How much energy is
required to lift the crate onto the dock?
a. 15 foot-pounds
b. 3 foot-pounds
c. 18 foot-pounds
d. 45 foot-pounds
Applied Technology • 41
1
LESSON 2
ANSWERS TO EXERCISE
1.
Mary wore a pair of thick gloves when she went snow skiing.
What principle is Mary using to keep her hands warm?
Answer: b. insulation
2.
Dan checks the level of motor oil in his boat every weekend
before taking it out. What principle is Dan aware of and
trying to prevent?
Answer: d. friction
3.
What material should Josh select to use as a conductor of
an electric current?
Answer: d. copper
42 • Applied Technology
1
4.
LESSON 2
Craig wants George to learn to scuba dive. George is afraid.
From the size of the tanks, he thinks the air will run out
while he is under the water. What principle should Craig
try to explain to convince George to dive with him?
Answer: b. compressed air
5.
Cain must lift a wooden crate 3 feet to place it on the loading
dock. The crate weighs 15 pounds. How much energy is
required to lift the crate onto the dock?
Answer: d. 45 foot-pounds
Applied Technology • 43
LESSON 3
1
MECHANICS: AN OVERVIEW
Well, I hope you survived the first two lessons
describing some basic ideas and principles of
science. You probably thought you were in
General Science class. I remember asking myself,
“How am I ever going to use this information?”
I hope I was able to show you how we use these
principles in a practical way every day!
In Lesson 3, we’re going to move into
mechanics and machinery. Our goal again will
be to give you information on the principles.
Also, we will show you practical ways these
principles are used.
Machines
A machine is simply something that does
work. Work is done when a force causes an object
to move. Man invented machines thousands of
years ago when he realized the limitations of the
human body as it applied to basic survival.
In the Stone Age, man realized he did not
have the physical ability to obtain the food he
needed to survive. He learned to use a club, a
rock, and later, invented the spear to help him
hunt for food. Traps were devised to catch
animals. All of these things that did work were
machines.
44 • Applied Technology
1
LESSON 3
Later, other machines were invented to make
work easier and faster. Man discovered that by
taking a long pole and placing it correctly, he
could lift boulders larger than ones he could lift
with his own strength. He had discovered the
lever! The lever is a simple machine, but WOW,
what a difference it makes!
In this lesson, we are going to briefly describe
simple machines, but we will focus on the
inclined plane and the lever. The principles
learned about these two machines will help you
better understand the operation of other
machines covered in later levels of Applied
Technology.
Applied Technology • 45
LESSON 3
1
Simple Machines
A machine transmits force and directs the
motion of the force. Some machines are called
simple machines. Others are combinations or
adaptations of simple machines. (Reference
sources differ as to which ones are simple
machines or adaptations.) In this course, we will
describe those machines considered as simple
machines. Then, we will focus on two of them.
Machines identified as simple machines are:
•
•
•
•
•
•
•
the inclined plane
the lever
the wheel and axle (a version of the lever)
the pulley (a version of the wheel and axle)
the gear (a version of the pulley)
the wedge (a version of the inclined plane)
the screw (a version of the inclined plane)
A machine’s capability to do work is measured
by its efficiency and mechanical advantage. As
we discussed earlier, no machine is 100%
efficient as a result of energy loss due to friction.
While no machine can be friction-free, steps
such as lubrication and design can be taken to
reduce friction. We’ll take a closer look at this
notion of mechanical advantage as we discuss the
inclined plane and the lever.
46 • Applied Technology
LESSON 3
1
Simple Machines
Figure 6
Inclined Plane
Figure 8
Wheel & Axle
Figure 11
Wedge
Figure 7
Lever
Figure 9
Gears
Figure 10
Screw
Figure 12
Pulley
Applied Technology • 47
LESSON 4
1
MECHANICS:
THE INCLINED PLANE
The inclined plane is so simple, you may have
a problem considering it a machine. However,
it can be a powerful tool in adding to our
capability to do work.
t
2f
1 ft
full force
half
e
c
for
Figure 13
The purpose of this tool is to move a load to
a higher or lower level while reducing the force
required.
48 • Applied Technology
LESSON 4
1
Let’s look at an example. (See Figure 14.) In
this example, the goal is to lift a 250-pound box
from point A to point B. You could consider
point B the back of a truck. Now, I’m not sure
about you, but I know I could not lift that
weight. However, if I move the box to point C,
I’m pretty sure I could push it up the ramp or
inclined plane.
B
10
ft
2 ft
250
C
lb
A
Figure 14
How much force will have to be applied to
push the box up the inclined plane? That’s where
the mechanical advantage comes in. For the
purpose of showing mechanical advantage, let’s
assume no friction is present.
In this example, we want to lift the 250pound box up two feet. A quantity can be
obtained by dividing the length of the inclined
plane (10 ft) by the vertical distance (2 ft), which
the box must be raised. The ratio is called the
mechanical advantage. In this example, the ratio
is 5 to 1.
mechanical advantage = length of inclined plane
vertical distance
Applied Technology • 49
LESSON 4
1
To determine the force necessary to raise the
box, you will divide the weight of the box by
the mechanical advantage.
250(lb) ÷ 5(advantage) = 50 lb of force
I will have to move the box farther in order
to raise it up the desired height, but now I can
do the work.
By making the same inclined plane longer,
we could further increase the mechanical
advantage. This means it would require even less
force to move the box. If we made the plane 20
feet long, we would have a mechanical advantage
of 10 to 1. (See Figure 15.) This would require
only 25 pounds of force.
250 ÷ 10 = 25
Of course, we would have to push the box
farther. As the slope of the inclined plane
decreases, the mechanical advantage increases.
B
20 ft
A
C
Figure 15
50 • Applied Technology
2 ft
LESSON 4
1
This principle is widely used in warehouse
and shipping applications. In some cases, the
ramps are made with rollers and bearings to
greatly reduce the friction. Some shipping and
manufacturing processes use motorized conveyor
belts on an inclined plane to move goods.
Our roads and walkways also use the inclined
plane principle. Automobiles slowly wind
around a mountain until they reach the top.
They travel a greater distance to reach the top.
However, vehicles have enough power to climb
the more gradual slope.
Another application we commonly see and
use is the escalator. While the escalator is a
complex machine, it is based on a motorized
conveyor moving up or down an inclined plane.
This allows the movement of large weight with
a reduced force.
Figure 16
Applied Technology • 51
LESSON 4
1
EXERCISE – INCLINED PLANE
Instructions:
Study the following diagrams. Select the letter of the response
that best answers each question.
25 ft
5 ft
100 lb
1.
What is the mechanical advantage of this inclined plane?
a. 5 to 1
b. 20 to 1
c. 4 to 1
d. 25 to 1
2.
How much force must be used to push the box up this
inclined plane?
a. 25 pounds
b. 100 pounds
c. 5 pounds
d. 20 pounds
3.
How much force must be used to lift the box if the inclined
plane were not used?
a. 25 pounds
b. 100 pounds
c. 5 pounds
d. 20 pounds
52 • Applied Technology
LESSON 4
1
1
50lbs
10 ft
t
f
30
ESCALATOR
4.
What is the mechanical advantage of this inclined plane?
a. 30 to 1
b. 3 to 1
c. 5 to 1
d. 50 to 1
5.
How much force must be used to move this person up the
escalator?
a. 30 pounds
b. 15 pounds
c. 50 pounds
d. 150 pounds
Applied Technology • 53
LESSON 4
1
ANSWERS TO EXERCISE
25 ft
5 ft
100 lb
1.
What is the mechanical advantage of this inclined plane?
Answer: a. 5 to 1
25 ft (length of inclined plane)
5 ft (distance of rise)
divide by 5 to get a ratio of 5 to 1
2.
How much force must be used to push the box up this
inclined plane?
Answer: d. 20 pounds
100 lb (weight to be moved)
5 (mechanical advantage)
divide 5 into 100 to find the force needed
54 • Applied Technology
LESSON 4
1
3.
How much force must be used to lift the box if the inclined
plane were not used?
1
Answer: b. 100 pounds
The entire weight of the box must be lifted.
50lbs
10 ft
t
f
30
ESCALATOR
4.
What is the mechanical advantage of this inclined plane?
Answer: b. 3 to 1
30 = 3
10 1
5.
How much force must be used to move this person up the
escalator?
Answer: c. 50 pounds
150 ÷ 3 = 50
Applied Technology • 55
LESSON 5
1
MECHANICS: THE LEVER
The lever is a simple machine that provides a
great deal of force.
Effort
10 pounds
Load
10 pounds
Fulcrum
Load and Effort are EQUAL
Figure 17
The lever is made of a piece of material placed
over a pivot point called a fulcrum. In Figure
17, the pivot point or fulcrum is located in the
exact center of the material. It is fairly easy to
see that the amount of effort exerted on one end
of the material will place an equal amount of
force on the other end. The lever is a highly
efficient machine because the friction at the
fulcrum is very small.
Let’s look at the mechanical advantage of the
lever. For future discussions, we will refer to the
material placed on the fulcrum as the lever. (See
Figure 18.)
56 • Applied Technology
LESSON 5
1
Load
30 lb
Effort
10 lb
1
2
lever
3
1
Figure 18
In this example, you will note we still have the
lever and the fulcrum. However, we have now
moved the fulcrum to a point toward one end of
the lever. The lever is four feet long with three feet
on one side of the fulcrum and one foot on the
other side. With this arrangement, exerting a 10pound effort to the longer end of the lever (3 feet
from the fulcrum) will result in a 30-pound upward
force being felt on the load end (1 foot from the
fulcrum). This again is mechanical advantage.
The mechanical advantage is the ratio developed
by comparing the length of the lever from the center
of the effort to the fulcrum and the length of the
lever from the fulcrum to the center of the load. In
this example, the mechanical advantage is 3 to 1.
mechanical advantage = length from fulcrum on effort side
length from fulcrum on load side
Applied Technology • 57
LESSON 5
1
Let’s take the same illustration but use a feetlonger lever. This time we’ll use a 12-foot
lever. The fulcrum is placed 2 feet from the load
end. What is the mechanical advantage? How
much effort will have to be exerted on the lever
to lift a 250-pound load?
I think you’re right! Let’s see … we have 10
feet on the effort side and 2 feet of the lever on
the load side. 10 divided by 2 equals 5 … so we
have a 5 to 1 mechanical advantage. We’re almost
there. In order to lift a load of 250 pounds when
I have a 5 to 1 mechanical advantage, I will have
to exert 50 pounds of force.
250 ÷ 5 = 50
Boy, I’m glad I got through that! However, it
was a lot easier than lifting all 250 pounds by
myself!
Effort
50 pounds
Load
250 pounds
Fulcrum
Figure 19
58 • Applied Technology
LESSON 5
1
There’s another point you need to understand
about the principles of the lever. The lever
machine we have been discussing is called a firstclass lever. The longer the effort side of the lever,
the greater the mechanical advantage. However,
with the use of this type of lever, you lose
distance. Distance from the fulcrum on the effort
side is directly related to the mechanical
advantage. Let’s think about the exercise we just
completed.
Effort
50 pounds
In Figure 20, we have a 5 to 1 mechanical
advantage. We can move 250 pounds with 50
pounds of effort. However, the load will move
only one increment of distance for every 5
increments of distance moved by the effort. Let’s
explain that another way. If I want to move the
load up 6 inches, I must move the lever, at the
effort end, down 30 inches. I gained force while
I lost distance.
Load
250 pounds
30 inches
6 inches
Fulcrum
Figure 20
First-Class Lever
Applied Technology • 59
LESSON 5
1
Thinking Activity
Look at the following drawing. What effort must be applied to
balance the 60-lb load?
60 lb
<
Answer: This may be tough! In this case, the load has the advantage
since it is on the longer side of the lever. The mechanical
advantage is 1 to 3. Therefore, you will have to exert 180-lb
effort to balance the 60-lb load.
60 • Applied Technology
LESSON 5
1
Everyday Applications
From our discussion, you should see the
advantage of using a lever to move a boulder in
your yard. There are also many other examples
that we use every day.
.
A
Figure 21
This is a common mechanic’s wrench. This
is used to tighten and loosen nuts and bolts with
far greater force than we can with our fingers.
With the wrench, we are using a lever to leverage
or increase the force. In this case, the nut or bolt
is the fulcrum, and the handle of the wrench is
the lever. The longer the handle, the more force
is developed. Also, notice that Point A of the
wrench travels a much greater distance than the
nut or bolt turns.
Applied Technology • 61
LESSON 5
1
Do you recognize the tool in Figure 22?
Figure 22
This is a claw hammer. The claw is used to
remove nails. Can you identify the fulcrum, the
lever effort point and the force point? I think
you’re starting to catch on.
Effort
Force
Nail
Fulcrum
Figure 23
62 • Applied Technology
1
LESSON 5
Identify the effort point, the fulcrum, and
the force point for each tool.
Figure 24
Crowbar
Figure 25
Pliers
Figure 26
Doorknob
Now turn the page to check your answers.
Applied Technology • 63
LESSON 5
1
Effort
Force
Fulcrum
Force
Fulcrum
Effort
Effort
Figure 24
Crowbar
Figure 25
Pliers
Effort
Point
Lever
Fulcrum
and
Force Point
Figure 26
Doorknob
NOTE: Figure 26 may have been a little tough, but I wanted to show variations
of how the lever principles are used.
64 • Applied Technology
LESSON 5
1
CE
N
E
CIRCUMFE
CUMF
CIR
ER
In the case of the doorknob, the outside
circumference of the doorknob represents the
effort point. The center of the doorknob is the
fulcrum.
CE
EN
R
Figure 27
Applied Technology • 65
LESSON 5
1
In addition to first-class levers, there are two
more classes of levers. I will describe them for
your information, but we will not cover them
in great detail.
A second-class lever is one that has the load
placed between the fulcrum and the effort point
on the lever. (See Figure 28.)
Load
Effort
Fulcrum
Figure 28
Second-Class Lever
66 • Applied Technology
LESSON 5
1
In this type lever, the load is supported by
both the fulcrum and the effort point. From
what we have previously discussed and logic, you
can conclude that a load placed in the exact
center will be equally supported by the effort
point and the fulcrum. When the load is moved
closer to the fulcrum, the fulcrum will support
more of the load and the effort point less. (See
Figure 29.) Conversely, the more the load is
moved toward the effort point, the more effort
it will take to support the load. (See Figure 30.)
Load
Fulcrum
LESS Effort
Figure 29
Load
Fulcrum
MORE Effort
Figure 30
Applied Technology • 67
LESSON 5
1
The wheelbarrow is a good example of a
second-class lever.
Load
Effort
Fulcrum
Figure 31
A third-class lever is one that has the effort
point between the load and the fulcrum. (See
Figure 32.)
Load
Fulcrum
Effort
Figure 32
Third-Class Lever
68 • Applied Technology
LESSON 5
1
In this application, you sacrifice power but
gain distance. If the effort point is at the same
point as the load, it will take an effort equal to
the load to support the load. (See Figures 33,
34, and 35.)
Distance
Figure 33
Load
Effort
Figure 34
Figure 35
The household broom is an example of a
third-class lever.
Fulcrum
Effort
Load
Figure 36
The distance the load travels will be greater
than the distance traveled at the effort point.
Applied Technology • 69
1
LESSON 5
EXERCISE – LEVERS
Instructions:
1.
Read each question. Select the letter of the response that best
answers the question.
The fulcrum is in the center of the lever. How much effort is
needed to balance the lever if 50 pounds are placed on one
end?
a. 25 pounds
b. 50 pounds
c. 100 pounds
d. 150 pounds
2.
Chris has a lever that is three feet long. There are two feet
on one side of the fulcrum and one foot on the other side.
What is the mechanical advantage that can be gained from
the lever?
a. 1 to 1
b. 2 to 1
c. 3 to 1
d. 6 to 1
70 • Applied Technology
1
3.
LESSON 5
With a 2 to 1 mechanical advantage, how much effort must
be applied to the lever to lift a 60-pound load?
a. 20 pounds
b. 30 pounds
c. 60 pounds
d. 120 pounds
4.
Don has been learning about the principles of levers. He
needs to lift a crate in his basement that weighs 100 pounds.
If he can attain a 4 to 1 mechanical advantage, he will only
have to exert 25 pounds of effort. Where does he need to
place the fulcrum for a 5-foot lever?
a. 4 ft on the side with the 100-pound load
b. 3 ft on the side with the effort
c. 1 ft on the side with the load
d. place fulcrum on end of lever with effort
Applied Technology • 71
LESSON 5
1
5.
Look at the drawing of a pair of scissors. Points A show
the:
A
C
A
B
a. effort
b. fulcrum
c. force
d. This tool does not use the principle of levers.
6.
Look at the drawing again. Point B shows the:
a. effort
b. fulcrum
c. force
d. This tool does not use the principle of levers.
72 • Applied Technology
LESSON 5
1
7.
Look at the drawing of a wedge. Point B shows the:
A
B
a. effort
b. fulcrum
c. force
d. This tool does not use the principle of levers.
8.
Look at the drawing of a fishing rod. Point C shows the:
C
B
A
a. effort
b. fulcrum
c. force
d. This tool does not use the principle of levers.
Applied Technology • 73
1
LESSON 5
ANSWERS TO EXERCISE
1.
The fulcrum is in the center of the lever. How much effort is
needed to balance the lever if 50 pounds are placed on one
end?
Answer: b. 50 pounds
2.
Chris has a lever that is three feet long. There are two feet
on one side of the fulcrum and 1 foot on the other side.
What is the mechanical advantage that can be gained from
the lever?
Answer: b. 2 to 1
3.
With a 2 to 1 mechanical advantage, how much effort must
be applied to the lever to lift a 60-pound load?
Answer: b. 30 pounds
74 • Applied Technology
1
4.
LESSON 5
Don has been learning about the principle of levers. He
needs to lift a crate in his basement that weighs 100 pounds.
If he can attain a 4 to 1 mechanical advantage, he will only
have to exert 25 pounds of effort. Where does he need to
place the fulcrum for a 5-foot lever?
Load
Effort
25 lb
100 lb
Answer: c. 1 ft on the side with the load
Applied Technology • 75
LESSON 5
1
5.
Look at the drawing of a pair of scissors. Points A show
the:
A Effort
C Fulcrum
A Effort
B Force
Answer: a. effort
6.
Look at the drawing again. Point B shows the:
Answer: c. force
76 • Applied Technology
LESSON 5
1
7.
Look at the drawing of a wedge. Point B shows the:
A
B
Answer: d. This tool does not use the principle of levers.
The wedge uses the principle of the inclined
plane.
8.
Look at the drawing of a fishing rod. Point C shows the:
C
B
A
Answer: c. force
Applied Technology • 77
LESSON 6
1
Well, that’s the last exercise on this level. Now,
that wasn’t too painful was it? It is time for you
to take a Posttest. Don’t get nervous. This will
help you to know how much you understand
about Level 1. If you feel you are not ready, just
go back and review the material first.
I will provide the answers so that you can
check yourself at the end of the Posttest. Don’t
be tempted to look ahead!
If you don’t do well, you can go back, review,
and retest yourself. I know you will do just fine.
Good luck!
No Peeking!
78 • Applied Technology
POSTTEST
1
EXERCISE – POSTTEST
Instructions:
Study the following diagram. Select the letter of the response that
best answers each question.
120 lb
12
1.
ft
3 ft
What is the mechanical advantage of this inclined plane?
a. 12 to 1
b. 25 to 1
c. 3 to 1
d. 4 to 1
2.
How much force must be used to push the box up the
inclined plane?
a. 30 pounds
b. 36 pounds
c. 120 pounds
d. 40 pounds
Applied Technology • 79
1
3.
POSTTEST
How much force must be used to lift the box if the inclined
plane were not used?
a. 30 pounds
b. 36 pounds
c. 120 pounds
d. 40 pounds
Instructions:
4.
Select the letter of the response that best answers each question.
Why does a piece of cork float when placed in water?
a. The volume of the water is greater than the volume of the
cork.
b. The density of the cork is less than that of the water.
c. The weight of the cork is greater than the weight of the
water.
d. Molecules of cork are much more densely packed than
those in water.
5.
What form of matter has very little movement of molecules?
a. solids
b. liquids
c. gases
d. atoms
80 • Applied Technology
1
Instructions:
6.
POSTTEST
Read each description of something that happens. Then, read the
question(s) about it. Select the letter of the process that you think
has occurred.
Kay recently started wearing glasses. She notices her
glasses fog up for a few seconds when she opens the oven
door to check the beef roast.
What principle causes the problem with Kay’s glasses?
a. evaporation
b. condensation
c. insulation
d. reflection
7.
Lin and Sue work together at a shipping warehouse. They
decided to visit an amusement park with a famous roller
coaster on their day off. Sue could hear the motor working
hard as they were pulled to the top of the track.
Which of the following principles causes a roller coaster
to move downhill on the tracks?
a. conduction
b. absorption
c. gravity
d. condensation
8.
Look at the drawing of a bottle opener. Point A represents
the:
Applied Technology • 81
POSTTEST
1
A
B
C
a. effort
b. fulcrum
c. force
d. This tool does not use the principle of levers.
9.
Look at the drawing of the bottle opener again. Point B
represents the:
a. effort
b. fulcrum
c. force
d. This tool does not use the principle of levers.
10. Look at the drawing of a hand cart. Point A represents the:
82 • Applied Technology
POSTTEST
1
A
C
a. effort
B
b. fulcrum
c. force
d. This tool does not use the principle of levers.
11. How many cubic feet are in a cubic yard?
a. 3 cubic feet
b. 27 cubic feet
c. 12 cubic feet
d. 1,728 cubic feet
12. Kyle started working at a produce warehouse. His first day
at work he noticed rolling balls under the belts that moved
Applied Technology • 83
1
POSTTEST
the produce to the loading docks. Ramps were used to load
the produce into the trucks. The balls under the belts are
used to:
a. increase speed
b. reduce condensation
c. increase pressure
d. reduce friction
13. The ramps at the loading dock are examples of:
a. inclined planes
b. levers
c. pulleys
d. wheel and axle
14. Ingrid has always washed her car in her driveway with the
water hose. Last week, she stopped at an automatic car
wash on her way home from work. She was amazed at the
force of the water.
What would make the difference in the force of the water?
a. The car wash uses more water than most homes, so the
water company gives them more water.
b. The car wash uses pressurized water, which gives the
water more force.
c. The car wash uses the principle of condensation to make
the water have more force.
d. The car wash has a mechanical advantage because the
hose is placed on a fulcrum.
84 • Applied Technology
1
POSTTEST
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Applied Technology • 85
POSTTEST
1
ANSWERS TO EXERCISE
120 lb
12
1.
ft
3 ft
What is the mechanical advantage of this inclined plane?
Answer: d. 4 to 1
12(length of plane) 4
=
3(distance of rise) 1
2.
How much force must be used to push the box up the
inclined plane?
Answer: a. 30 pounds
120 lb (weight to be moved)
4 to 1 (mechanical advantage)
divide 120 by 4 to find the force needed with the
mechanical advantage of 4 to 1
86 • Applied Technology
1
3.
POSTTEST
How much force must be used to lift the box if the inclined
plane were not used?
Answer: c. 120 pounds
4.
Why does a piece of cork float when placed in water?
Answer: b. The density of the cork is less than that of the
water.
5.
What form of matter has very little movement of molecules?
Answer: a. solids
6.
Kay recently started wearing glasses. She notices her
glasses fog up for a few seconds when she opens the oven
door to check the beef roast.
What principle causes the problem with Kay’s glasses?
Answer: b. condensation
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POSTTEST
1
7.
Lin and Sue work together at a shipping warehouse. They
decided to visit an amusement park with a famous roller
coaster on their day off. Sue could hear the motor working
hard as they were pulled to the top of the track.
Which of the following principles causes a roller coaster
to move downhill on the tracks?
Answer: c. gravity
8.
Look at the drawing of a bottle opener. Point A represents
the:
A
B
88 • Applied Technology
C
POSTTEST
1
9.
answer: b. fulcrum
Look at the drawing of the bottle opener again. Point B
represents the:
Answer: c. force
10. Look at the drawing of a hand cart. Point A represents the:
A
C
B
Answer: c. force
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POSTTEST
1
11. How many cubic feet are in a cubic yard?
Answer: b. 27 cubic feet
There are 3 feet in a yard.
3 feet × 3 feet × 3 feet = 27 cubic feet
t
3 feet
ee
3f
1 ft
3 feet
12. Kyle started working at a produce warehouse. His first day
at work he noticed rolling balls under the belts that moved
the produce to the loading docks. Ramps were used to load
the produce into the trucks. The balls under the belts are
used to:
Answer: d. reduce friction
13. The ramps at the loading dock are examples of:
Answer: a. inclined planes
90 • Applied Technology
1
POSTTEST
14. Ingrid has always washed her car in her driveway with the
water hose. Last week, she stopped at an automatic car
wash on her way home from work. She was amazed at the
force of the water.
What would make the difference in the force of the water?
Answer: b. The car wash uses pressurized water, which
gives the water more force.
Applied Technology • 91
YOUR SCORE
1
The following chart will provide you with scoring information. Count the
number of correct answers on your Posttest. Find that number in the left
column. The number in the right column is your score. Repeat the exercises
that you missed and, if needed, go back to the lesson that talks about those
topics.
NUMBER OF
CORRECT ANSWERS
SCORE
15
100%
14
93%
13
87%
12
80%
11
73%
10
67%
below 9
review entire
level
92 • Applied Technology
1
SUMMARY
Well, how did you do on the Posttest? If you
scored 87% or higher, you are ready for Level 2.
Don’t be discouraged if you scored below 87%.
There are a lot of skills to learn. You can do it!
Remember, Applied Technology skills will help
you in the workplace and throughout your life.
Good
Job!
Applied Technology • 93
REFERENCE
1
GLOSSARY
adaptation - the process of adjusting or changing forms
alloy - different types of metals that have been melted and blended
together
bearing - a machine part to reduce friction on which parts turn or slide
circumference - the perimeter or outside distance around a circle
compound - made up of two or more parts
compression - a process of pressing or squeezing together
condensation - the process of a gas changing into a liquid
conduction - the transfer of heat through matter or the passage of
electricity
conduit - a path or channel
cylinder - long, round body or figure
density - a measure of the closeness of molecules in matter. Density is
the ratio of mass to volume.
electricity - a form of energy comprising elementary particles that exert
force on one another
energy - the capacity for doing work
evaporation - the process of changing a liquid into a gas
fluid dynamics - the use of liquids and pressure
foot-pound - the measure of work or energy required to move an object
one foot against one pound of resistance
force - a push or pull
friction - creation of resistance and heat when matter rubs against matter
gravity - attraction of matter toward the center of the earth
heat - form of energy transferred between two bodies as a result of their
94 • Applied Technology
1
REFERENCE
differences in temperature
hydraulics - the use of pressure transmitted through liquids to exert
force
inertia - tendency of matter to remain at rest or in motion
insulation - the effect of limiting the amount of transfer of heat,
electricity, sound, or other forms of energy
lubricant - substance that reduces friction
matter - material substance of which any physical object is made
mechanical advantage - a gain from the use of a machine to transmit
force
mechanics - a science that deals with energy and forces and their effects
on bodies
molecule - small particles that make up matter
molten - melted or made into liquid by heat
particles - any of the basic units of matter
pressure - force per unit area
principle - a law or fact of nature
reflection - the act of bending or throwing back energy, such as light,
heat, or sound
resistance - an opposing force
sphere - round body; a globe
technology - the use of tools or methods to do work more easily
thermodynamics - the influence and use of heat
wave - fluctuation that transfers energy from point to point
weight - a measurement of gravity’s pull on forms of matter; a measure
of heaviness
Applied Technology • 95
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