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AIM: How are energy
Conversions and Energy
conservation related?
AIM: How are energy Conversions
and Energy conservation related?
Identify and describe energy conversions
State the law of conservation of energy
Identify how the two vocabulary terms
are related
AIM: How are energy Conversions
and Energy conservation related?
ENERGY CONVERSIONS
ENERGY CONSERVATIONS
AIM: What are energy conversions, etc.
Rub your hands together.
What type of energy is produced?
Where did that energy come from?
Did an energy conversion take place?
AIM: What are energy conversions, etc.
What was that Energy Conversion?
AIM: What are energy conversions, etc.
When I strike a tuning fork --What type of energy is produced?
Where did that energy come from?
…moving your hands (mechanical)
Is that an energy conversion
AIM: What are energy conversions, etc.
Is that an energy conversion?
What is the energy conversion?
AIM: What are energy conversions, etc.
AIM: What are energy conversions, etc.
What is an ENERGY CONVERSION?
Definition #1:
Energy can {and does} change
form, from one type of energy to
another
What is an ENERGY CONVERSION?
Definition #2:
Typically when energy changes from
one form to another …
Heat is sometimes produced as a
by-product
What energy conversions exist here?
Electrical to …
HEAT
What energy conversions are present?
Electrical …
to MECHANICAL…(the motor & wind)
To HEAT…
What energy conversions exist here?
…Electrical to
Electromagnetic (light) … with
Heat…as a by-product !
What energy conversions are present?
Write that down!
EM waves of
the sun are
turned into
chemical
energy
Green plants turn the energy of the sun
into ???
FOOD or Glucose
Glucose is a form of what type of energy
???
CHEMICAL ENERGY
What energy conversions are present?
Electrical into electromagnetic -
microwaves
What energy conversions exist here?
Food (chemical) to energy …
To physical movement by the
muscles
The Chemical Energy (food)
to electrical (brains and nerves)
AND to mechanical (playing ball!)
AIM: What are energy conversions, etc.
What does CONSERVATION mean?
Main Entry: con·ser·va·tion
Pronunciation: "kän(t)-s&r-'vA-sh&n
Function: noun
Etymology: from Latin
“preservation”
“to keep constant”
“to not loose any of”
“to save”
AIM: What are energy conversions, etc.
Law of Conservation of Energy:
“When energy changes from
one form to another,
energy is neither created
nor destroyed -- but
merely changes form”
“energy is neither created
nor destroyed”
AIM: What are energy conversions, etc.
Lets examine the match
AIM: What are energy conversions, etc.
What energy conversions occur with
a match?
Mechanical causes the strike
AIM: What are energy conversions, etc.
The strike creates friction
Friction cause what ???
Thermal which is heat
AIM: What are energy conversions, etc.
The Heat Causes …
INGNITION
- releases the stored chemical
energy in the “match head”
AIM: What are energy conversions, etc.
Burning of the chemical energy
Produces
light
& heat!
AIM: What are energy conversions, etc.
WHAT IS THIS MACHINE?
What does it run on ??
AIM: What are energy conversions, etc.
What is that called?
Solar Cell
What energy conversion occurs
in a solar cell?
AIM: What are energy conversions, etc.
The Solar Cell
•Transforms Light!
•Light hits the solar cell, and
transforms to what?
AIM: What are energy conversions, etc.
Does a calculator need a lot of
Electricity?
•Therefore how much electricity do
you think a solar cells produces ?
What is this person doing?
Which ball has the greatest potential energy?
Which ball has the least potential energy?
Analyze this Pendulum
that means copy it in your notebook
Where is the greatest Potential
energy?Label your diagram!
Where is the greatest Potential
energy?Label your diagram!
Analyze this Pendulum
Where is the least Potential energy?
Label your diagram!
Where is the least kinetic energy?
Label your diagram!
Where is the least kinetic energy?
Label your diagram!
Analyze this Pendulum
Where is the greatest kinetic energy?
Label your diagram!
Analyze this Pendulum
As the pendulum moves back and forth
The type of energy amongst point 1,2,& 3
is constantly changing form
Potential
to Kinetic
and back
again!
What forms of energy are
constantly changing in a pendulum?
Analyze this Pendulum
Will the pendulum swing for ever?
NO!
What eventually causes it to stop?
F R I C T I O N (air resistance)
Why?
When Energy transfers form what happens ?
Some of the energy is usually lost to heat (friction)
Detailed Look:
Analyze this Pendulum
that means copy it in your notebook
Let’s Assume the energy of this
total Pendulum system equals 2
Think about the Law of Conservation
of energy and how it applies to the
pendulum with an energy value of 2
As pendulum moves from position to
position, at any given point its total
energy value will remain at 2.
WHY?
Because energy is neither created nor
destroyed when it changes from one
form to another!
When the pendulum is just
starting, all of its energy is at
position #1. What is that value?
And, what was the total energy of the
entire pendulum system?
What is the total energy at position #3?
PE = 2
What Law tells us the total PE
MUST be 2 position #3?
Law of
Conservation
of energy
What does the Law of Conservation of
Energy state ???
Energy is
neither
created not
destroyed
So, if the P.E value of the pendulum at
position #1 is 2. And if the value of the
entire energy system is 2…
What is the
value of the
Kinetic
Energy at
position 1?
So, if the P.E. value of the pendulum at
position #3 is 2. And if the value of the
entire energy system is 2…
What is the
value of the
Kinetic
Energy at
position 3?
Let’s examine Position #2.
What is the potential energy of #2?
Position 2 has
Zero potential
energy
So if Position #2 has zero potential
energy. But the total energy value of
the system is 2 ….
What must
be the KE
value of
position
#2?
What does law of conservation of
energy state?.
Energy is
neither
created nor
destroyed
Could you Graph the Energy
of a Pendulum
2
1.5
Total Energy
of Pendulum
1
K.E
P.E.
0.5
0
Postion 1
Position 2
Position 3
Pendulum Positoins
Assumes the energy of the system is a “hypothetical 2”
Can you Graph a more complex
example of the Pendulum
2
1.5
Total Energy
of Pendulum
1
K.E
P.E.
0.5
0
Postion 1 Position Position Position Position
A
2
B
3
1
Pendulum Positoins
3
A
B
2
Energy of the system is a “hypothetical 2”
AIM: What are the energy types?
Worksheet Concepts 3-3, 3-4
Concept Enrichment W/S #13
PH Worksheet # 13-2
PH Enrichment # 13-2
PH Worksheet #13-1 Identify the
conversions that have taken place!
AIM: What are energy conversions?
Homework:
INTERNET QUESTIONS
FINISH WORKSHEETS
*** Performance Assessment:
The Nature of Energy Assess
students' understanding of the
nature of energy by having them
draw a sketch or diagram of
playground equipment and label
positions where a child would have
potential energy and kinetic
energy.
13-1