Transcript Potential energy

Big Idea:
Energy Exits in different forms and can
change from one form to another, but
energy is always conserved.
Unit 2 Lesson 1
Introduction to Energy
Essential Question:
What is energy?
X
X
X
X
Sound from this marching
band is caused by
vibrations of air particles
A law that states that energy
cannot be created or
destroyed but can change
forms
Unit 2 Lesson 1 Introduction to Energy
Get
Energized!
p102
What are two types of energy?
• Energy is the ability to cause change.
• Energy takes many different forms and causes
many different effects.
• There are two general
types of energy:
• kinetic energy
• potential energy
Unit 2 Lesson 1 Introduction to Energy
p102
What are two types of energy?
• Kinetic energy is the mechanical energy of an object that is
due to motion. All moving objects have kinetic energy.
• The amount of kinetic energy an object has depends on its mass
and speed (Velocity).
• Kinetic energy increases as mass increases and as velocity
(speed) increases.
Unit 2 Lesson 1 Introduction to Energy
p103
What are two types of energy?
• Potential energy is the mechanical energy that an object
has due to its position, condition, or chemical composition.
• Potential energy that is the result of an object’s position is
called gravitational potential energy.
• Gravitational potential energy increases as the object’s
height or mass increases.
Unit 2 Lesson 1 Introduction to Energy
p103
What are two types of energy?
• Potential energy is the mechanical energy that an object
has due to its position, condition, or chemical composition.
• Potential energy that is the result of an object’s condition
is called elastic potential energy.
• A change in the condition of an object affects its
potential energy.
• Stretching a rubber band increases its potential
energy
Unit 2 Lesson 1 Introduction to Energy
p103
What are two types of energy?
• Potential energy is the mechanical energy that an object
has due to its position, condition, or chemical composition.
• Potential energy that is the result of an object’s chemical
composition is called chemical potential energy.
• Chemical potential energy depends on chemical
composition.
• As bonds break and new bonds form between atoms
during a chemical change, energy can be released.
Fuels such as charcoal are hydrocarbons, chemical
compounds made mainly from hydrogen and carbon.
When a fuel burns in air, the hydrocarbons break up
into simpler compounds. The chemical potential energy
they contain is then released as heat energy. Light
energy is produced at the same time and this is what
makes a fire glow as it burns
Unit 2 Lesson 1 Introduction to Energy
p103
6) Other things that show PE & KE
Unit 2 Lesson 1 Introduction to Energy
p103
Can objects have potential and kinetic energy
at the same time?
• An object can have both potential and kinetic energy at
the same time.
The story of kinetic and
potential energy
Unit 2 Lesson 1 Introduction to Energy
p103
7) Analyze: Do you think that the skater has any
GPE at pt C (3)? Explain
• No, because he is at the bottom of the ramp.
• Gravity cannot pull him any lower, so he has no GPE
Energy transfer inside a half pipe.
1 & 5) All potential energy
2) Potential becoming Kinetic
3) All Kinetic energy no Potential
4) Kinetic becoming Potential
5) All Potential
• The Come-Back Can – Lab Section
• Take out key terms and put on corner of
desk.
• Planner/Yellow card on top of key terms
– open to today’s date.
• Open book to p104
• Write name on all papers on your desk
P104-106 notes
In Perfect Form WS (homework)
Unit 2 Lesson 1 Introduction to Energy
p104
In Perfect Form
What forms can energy take?
• Kinetic energy and potential energy are two
types of energy that can come in many
different forms.
• mechanical, sound, electromagnetic,
electrical, chemical, thermal, and
nuclear energy.
• Energy is expressed in joules (J).
P104-105
Mechanical Energy
•
•
•
•
Sum of Kinetic and Potential Energy
Energy of Position and Motion
Moving car
Can be all kinetic, all potential or a combination
P104-105
Electromagnetic
Energy
Sound
Energy
• Kinetic Energy
• Vibration of
particles of the
medium it’s
traveling
through
• Kinetic Energy
• Travels through
space in
electromagnetic
waves
• Vibrations of
electrically charged
particles.
• Electric and Magnetic
Properties
• X-rays, microwaves,
visible light, sun
Electrical Energy
• Kinetic and
Potential Energy
• Position and
Motion of charged
particles
(electrons –
negative)
• Lights, computer
Thermal energy
Chemical
Energy
• Potential Energy
• Bonds break and
new bonds form.
• Food, batteries,
matches
• Kinetic Energy
• Particles are in
motion
• As motion
increases, KE
increases,
Temperature
increases
• Heat is energy
transferred from
the area of higher
temp to area of
lower temp
P104-105
Nuclear Energy
• Potential Energy
• Nucleus of an
atom is the
source.
• Fission: nucleus
splits (breaks
apart)
• Fusion: Nuclei
join together
• Energy is
released
• SUN
Unit 2 Lesson 1 Introduction to Energy
P104-105
9) How does electrical energy differ
from electromagnetic energy?
Electromagnetic energy is caused by vibration of
electrically charged particles. Transmitted by waves
Electrical energy is caused by the position or motion of
electrically charged particles.
10) Would you expect to detect electrical
energy if you played the pinball game?
Explain
The pinball machine is powered by electrical energy as
inferred by the lights, sounds (rings where the ball hits
the bumper) and motion of the flippers.
Unit 2 Lesson 1 Introduction to Energy
In Perfect Form WS
1) You can determine an object mechanical
energy by adding together the objects kinetic
and potential energy.
2) 2 forms of energy associated with the particles
that make up the object are: Nuclear,
electromagnetic, electrical, chemical, thermal
or sound.
3) B,C,E,F (electrical, thermal, chemical, electromagnetic)
4) A (mechanical)
5) A,B,C,F (mechanical, electrical, thermal, electromagnetic)
6) B,C,F (electrical, thermal, electromagnetic)
7) C,D,F (thermal, nuclear, electromagnetic)
8) A,C,E,F (mechanical, thermal, chemical, electromagnetic)
Unit 2 Lesson 1 Introduction to Energy
P104-105
What forms can energy take?
8) What forms of energy can you identify in
this pinball game?
Electromagnetic
B
Sound
C
Mechanical
A
Copyright © Houghton Mifflin Harcourt Publishing Company
Unit 2 Lesson 1 Introduction to Energy
Pg 106
12) Why is the chemical energy of a battery
potential energy and not kinetic energy?
The energy in the chemicals is stored energy. The battery
must be placed into a completed electrical circuit for the
energy to create an electric current.
Unit 2 Lesson 1 Introduction to Energy
Pg 108-109
Transformers
What is an energy transformation?
• An energy
transformation takes
place when energy
changes from one form
into another form.
• Any form of energy can
change into any other
form of energy.
• Often, one form of energy
changes into more than
one form.
Unit 2 Lesson 1 Introduction to Energy
Pg 108-109
What is an energy transformation?
• In a flashlight, chemical energy (battery) is
transformed into electrical energy.
• The electrical energy is then transformed into light
and thermal energy.
Unit 2 Lesson 1 Introduction to Energy
Pg 108-109
Is energy conserved?
• A closed system is a group of objects that transfer
energy only to one another. Energy is conserved in all
closed systems.
• The law of conservation of energy states that energy
cannot be created or destroyed. It can only change
forms.
• All of the different forms of energy in a closed system
always add up to the same total amount of energy.
17) Relate
The law of conservations of energy states energy is not
created not destroyed: it can only change forms. An
energy transformation is a change from one form of
energy to another.
Unit 2 Lesson 1 Introduction to Energy
Pg 108-109
Energy Transformations when you strike a match?
__________
__________
and
__________
__________
__________ and
__________
Energy Transformations when you bounce a ball?
_____
_____
_____
_____
______________________
_____
_____
Unit 2 Lesson 1 Introduction to Energy
Pg 108-109
Energy Transformations when you strike a match?
1) Striking the match transforms mechanical energy to thermal
energy & sound energy.
2) Thermal Energy causes particles to release chemical energy.
3) Chemical energy is transformed to thermal and
electromagnetic energy.
Chemical
Potential
Mechanical
Thermal
& Sound
Chemical
Thermal (heat)
& Electromagnetic
(light)
Unit 2 Lesson 1 Introduction to Energy
Pg 108-109
Energy Transformations when you bounce a ball?
1) As the ball falls, gravitational potential energy is transformed to kinetic
energy.
2) While the ball is in contact with the floor, kinetic energy transforms into elastic
potential energy and then back to kinetic energy.
3) As the ball travels upward, kinetic energy is transformed to potential energy.
4) The ball does not return to original height because some K.E. is transformed
to Thermal energy or Sound during a bounce.
GPE
KE
EPE
KE
Thermal and Sound Energy
GPE
Unit 2 Lesson 1 Introduction to Energy
Space Weather and Technology
• Space weather includes any activity happening in
space that might affect Earth’s environment.
• Space weather can damage satellites and
interrupt phone signals and signals to Global
Positioning System (GPS) receivers.
• Auroras are caused by electrically charged
particles of solar winds hitting Earth’s magnetic
field. They can interrupt airplane communications.
Copyright © Houghton Mifflin Harcourt Publishing Company
Unit 2 Lesson 1 Introduction to Energy
Space Weather and Technology pg 107
13) Identify: what type of energy is monitored by scientists forecasting future
space weather?
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14) Infer: Why is space weather a bigger concern now than it was in the past?
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15) Research: How do scientists forecast space weather? Why?
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Copyright © Houghton Mifflin Harcourt Publishing Company
Unit 2 Lesson 1 Introduction to Energy
Space Weather and Technology pg 107
13) Identify: what type of energy is monitored by scientists forecasting future
space weather?
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
14) Infer: Why is space weather a bigger concern now than it was in the past?
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
15) Research: How do scientists forecast space weather? Why?
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
Copyright © Houghton Mifflin Harcourt Publishing Company
Energy
measured in
exists as
is the ability
to do
Work
can be
which at a
given rate is
Power
Draw and fill in into your
notes
Review
Energy
exists as
Kinetic
energy
Potential
energy
measured in
is the ability
to do
Joules
Work
can be
Elastic
Gravitational
which at a
given rate is
Power