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September 13, 2010
Agenda
 Types of Energy
 Introduction of Unit
Project
Homework
 Identify and
describe 5 different
renewable energy
sources used to
produce power to
our homes
BrainTeaser
 Fossil fuels (coal,
oil and gas) will
eventually run out.
Why are they called
“fossil” fuels?
 Why are they so
important to our
society?
Unit 3 Objectives
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Understand how energy is stored in
a system
Describe how energy is transferred
from one system to another
Energy is conserved in a closed
system
Energy:
Forms and
Changes
Nature of Energy
 Energy
is all around you!
You can hear energy as sound.
 You can see energy as light.
 And you can feel it as wind.
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Nature of Energy
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You use energy
when you:
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hit a softball.
lift your book
bag.
compress a
spring.
Nature of Energy
Living organisms need
energy for growth and
movement.
Nature of Energy
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Energy is involved
when:
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a bird flies.
a bomb explodes.
rain falls from the
sky.
rollercoasters rise
and fall
electricity flows in
a wire.
A burning
match
releases
energy.
Source:
ElektraVision/
PictureQuest
The sun is the
source of all energy
we use
Nature of Energy
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What is energy that it can be
involved in so many different
activities?
Energy Expert Jigsaw
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Begin by summarizing the
information in the article that your
group was assigned
Then form groups of 3—1
representative from each article
group
List Energy types and sources
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Use the notes that you made from
your article group.
Make a list of at least 30 words of
energy types and sources in your 3
person group
examples
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Nuclear
chemical
gasoline
electricity
batteries
fusion
oil
Mechanical
kinetic
potential
natural gas
Steam
food
light
microwaves
hydro
Fission
thermal
sound
x-rays
heat
Uranium
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wind
tides
hot water
gun powder
wound up spring toy
static cling
ball in motion
heavy water
hydro
solar
ultraviolet rays
turning drill bit
lightning
wood
stretched bungee cord
star light
heat lamp
stretched rubber band
charcoal
heavy water
compass
CHEMISTRY
September 15, 2010
Warm Up
 Name
5 sources of renewable
energy.
September 14, 2010
Agenda
 Warm Up
 Collect Unit 2 Review: Period 5
 Unit 3:
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The Law of Conservation of Energy
Energy Conversions
Information on Research Project
Homework
Energy Jigsaw Homework
Begin Project
Research
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What IS energy?
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Energy (E): The ability to do work or
produce heat (units of Joules or
KiloWatt hour)
Work (w): The capacity to move an
object over a distance against a
resisting force (units of Joules or
Newton-meters)
What IS energy?
 Because
of the direct
connection between energy and
work, energy is measured in
the same unit as work: joules
(J).
 In addition to using energy to
do work, objects gain energy
because work is being done on
them.
What about POWER?
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Power: the rate at which work can be
done, i.e. a measure of how quickly work
can be done (units of Watts)
Power is like the strength of a
weightlifter, energy is like his endurance.
The work the weightlifter does is moving
the weights from the ground to over his
head.
Can you think of other examples?
States of Energy
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All forms of energy can be in either
of two states:
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Potential
Kinetic
Potential Energy
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Energy due to the composition or
the position of an object
Composition: type of atoms, number and
types of chemical bonds and arrangement
of the atoms
 Position: objects waiting to fall off a shelf
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Potential Energy
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Potential Energy is stored energy.
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Stored chemically in fuel, the nucleus
of atom, and in foods.
Or stored because of the work done on
it:
Stretching a rubber band.
 Winding a watch.
 Pulling back on a bow’s arrow.
 Lifting a brick high in the air.
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Potential Energy
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Energy that is stored due to being
stretched or compressed is called
elastic potential energy.
Gravitational Potential Energy
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Potential energy
that is dependent
on height is called
gravitational
potential energy.
Gravitational Potential Energy
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A waterfall, a suspension bridge, and a
falling snowflake all have gravitational
potential energy.
Gravitational Potential Energy
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“The bigger they are the harder
they fall” is not just a saying. It’s
true. Objects with more mass have
greater G.P.E.
The formula to find G.P.E. is
G.P.E. = Weight X Height.
Kinetic Energy
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Kinetic
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Energy of motion
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moving objects, moving particles,
vibrating molecules, etc
Kinetic Energy
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The faster an object moves, the
more kinetic energy it has.
The greater the mass of a moving
object, the more kinetic energy it
has.
Kinetic energy depends on both
mass and velocity.
Forms of Energy
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The six main forms of energy are:
Electric
 Heat
 Chemical
 Electromagnetic (light)
 Nuclear
 Mechanical
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Other (gravitational, spring, magnetic)
Energy Jigsaw Assignment
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Group any types, sources, or
associated words that seem to refer
to the same type of energy.
You can do this using colored
pencils, or by making lists of each
set of words that seem to be a
given type of energy.
Try to get all of the words into 7
categories, one for each basic type
of energy.
Electrical (PE)
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flow of mobile electrons
A bolt of lightning contains enough
energy to toast 160,000 pieces of
bread. Unfortunately the bolt only
takes 1/10,000 of a second – so
turning the bread over might prove
difficult.
Heat / Thermal Energy (KE)
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The internal motion of the atoms is
called heat energy, because moving
particles produce heat
Heat energy can be produced by
friction.
Heat energy causes changes in
temperature and phase of any form
of matter.
heat as energy
Chemical Energy (PE)
 Chemical
Energy is required to
bond atoms together.
 And when bonds are broken,
energy is released.
Chemical Energy
 Fuel
and food are
forms of stored
chemical energy.
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One kilogram of butter
stores as much energy
between its atoms as
the same quantity of
TNT.
Frequencies of radiation in the electromagnetic
spectrum—waves are always in motion
Electromagnetic Energy (KE)
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Light is a form of
electromagnetic energy.
Each color of light (Roy G
Bv) represents a different
amount of
electromagnetic energy.
Electromagnetic Energy is
also carried by X-rays,
radio waves, and laser
light.
Did you know?
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If 10 kilograms of matter
spontaneously turned into energy
there would be enough energy to
power a 100 Watt light bulb for 300
million years!!!
Nuclear Energy (PE)
 The
nucleus
of an atom is
the source of
nuclear
energy.
Nuclear Energy
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When the nucleus splits (fission),
nuclear energy is released in the
form of heat energy and light
energy.
Nuclear energy is also released
when nuclei collide at high speeds
and join (fusion).
Nuclear Energy
The sun’s energy
is produced from
a nuclear fusion
reaction in which
hydrogen nuclei
fuse to form
helium nuclei.
Nuclear Energy
 Nuclear
energy is the most
concentrated form of energy.
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The amount of sunlight reaching the
earth's surface is 6,000 times the amount
of energy used by all human beings
worldwide. The total amount of fossil fuel
used by humans since the start of
civilization is equivalent to less than 30
days of sunshine.
Mechanical Energy (KE)
 The
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motion of objects
Kicking a football
Throwing a bowling ball
Check 4 Understanding
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Energy of stars
Energy of a substance changing
states (gas to liquid, liquid to
solid, etc)
Energy of batteries
Energy of tanning lamps
Clicking of a computer mouse
Energy of lightning
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Nuclear
fusion
Heat
Chemical
Light
(ultraviolet
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Mechanical
Electrical
Warm Up
 Classify
these forms of energy
as Kinetic or Potential energy
 Electric
 Heat
 Chemical
 Electromagnetic
 Nuclear
 Mechanical
(light)
September 14, 2010
Agenda
 The Law of
Conservation of
Energy
 Energy
Conversions
Homework
Begin Research
Unit 3 Worksheet 1
Law of Conservation of Energy
Energy cannot be created or
destroyed but it can change its
form.
Compound Machines
Energy IN = Energy OUT
Energy released = Energy absorbed
Energy of a system = Energy of
surroundings
The Law of Conservation of Energy
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Energy can be neither created nor
destroyed by ordinary means.
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It can only be converted from one form
to another.
If energy seems to disappear, then
scientists look for it – leading to many
important discoveries.
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System: whatever we’re studying
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Surroundings: everything outside the system
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Universe = system + surroundings
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If we’re studying a space heater, the heater will be our
system, the house will be our surroundings, and the
universe will be the heater and the house together (we
ignore the irrelevant rest of the world, since it doesn’t
really play a part in anything).
Energy Conversion
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Energy can be changed from one
form to another. Changes in the
form of energy are called energy
conversions.
Energy conversions
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All forms of energy can be
converted into other forms.
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The sun’s energy through solar cells
can be converted directly into
electricity.
Green plants convert the sun’s energy
(electromagnetic) into starches and
sugars (chemical energy).
Other energy conversions
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In an electric motor, electric energy is
converted to mechanical energy.
In a battery, chemical energy is
converted into electromagnetic energy.
The mechanical energy of a waterfall is
converted to electrical energy in a
generator.
Examples
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You can use the energy of moving
turbines (kinetic) to charge a
battery (potential)
You can take the stored gravitational energy of
a book on a shelf and make it into the kinetic
energy of the book moving through the air.
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Some people who have two or more
different kinds of fillings in their teeth are
able to hear high-power AM broadcast
stations when located within a few
hundred feet of the stations. In such
cases, the strong radio waves act upon
the teeth fillings in such a way that the
electromagnetic oscillations get
transformed to mechanical vibrations in
the person's head, and these are heard as
sound.
Energy Trace
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The objective is to illustrate how
energy is essential in our daily lives
by tracing back to where energy
starts.
First, identify a sequence of events.
Second, identify the type of energy
that is involved.
Third, identify the source of the
energy.
Waking up in the morning
Event
Type of Energy
Source
Alarm clock
wakes me up
Electrical/Sound
Power Company
Power company
distributes
electricity
Mechanical
Water
Snow melts to
make water
Thermal
Sun
Energy Conversions
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In an automobile
engine, fuel is
burned to convert
chemical energy
into heat energy.
The heat energy is
then changed into
mechanical
energy.
Chemical  Heat Mechanical
Kinetic-Potential Energy Conversion
Roller coasters work because of the energy that is
built into the system. Initially, the cars are pulled
mechanically up the tallest hill, giving them a great
deal of potential energy. From that point, the
conversion between potential and kinetic energy
powers the cars throughout the entire ride.
Kinetic vs. Potential Energy
At the point of maximum potential energy, the car has
minimum kinetic energy.
Kinetic-Potential Energy Conversions
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As a basketball
player throws the
ball into the air,
various energy
conversions take
place.
Ball slows down
Ball speeds up
Energy Research Project
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You will work in groups of 3
Pick your partners carefully
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Pick them for reliability and their
strengths in the following areas:
Designing a powerpoint
 Research and summarizing information
 cost benefit analysis (looking at all sides
of an issue and being objective)
 Working with a team
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Arizona Corporation Commission
Utilities
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SRP Salt River Project
APS Arizona Public Service
TEP Tuscon Electric Power
AIC Ajo Improvement Company
NEC Navopache Electric Cooperative
MEC Mohave Electric Cooperative
And more…..
The coal is burned in a boiler which produces steam. The steam is run through a turbine which turns a
generator which produces electricity. A turbine is like a fan in reverse, with many vanes or blades,
where the steam is used to make the turbine turn or rotate rapidly. A generator is a huge magnet that
is turned by the turbine. As the magnet turns inside a coil of wire, electricity is produced. So, the
energy chain for this power plant would look like this:
Chemical  Heat  Mechanical  Electrical
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energy plant game
http://www.fi.edu/guide/hughes/dis
cussiontopics.html
Vocabulary Words
energy
mechanical energy
heat energy
chemical energy
electromagnetic energy
nuclear energy
kinetic energy
potential energy
gravitational potential energy
energy conversion
Law of Conservation of Energy
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The second law of thermodynamics
is a general principle which places
constraints upon the direction of
heat transfer and the attainable
efficiencies of heat engines.
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Spontaneous processes always
proceed in such a way that the
entropy of the universe increases.
Entropy is a measure of disorder or
randomness of the particles that
make up a system.
Energy Efficiency
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No system is 100% efficient
With Energy, we look at the ratio of
the useful energy gotten out to the
energy put in
Generally, wasted energy is
observed as heat.
When researching your energy
technologies, be aware of the
engines and mechanical machines
which will lower your efficiencies.
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there has to be an energy transfer
for something to happen; energy
changes form or moves from place
to place
each time energy gets transferred
or transformed, some of it, and
eventually all of it, gets less useful
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Video:
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Efficiency_of_Energy_Conversions