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Unit 2 Lesson 1 Introduction to Energy
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Unit 2 Lesson 1 Introduction to Energy
Get Energized!
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 and potential energy.
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Unit 2 Lesson 1 Introduction to Energy
What are two types of energy?
• Kinetic energy is the 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.
• Kinetic energy increases as mass increases and as
speed increases.
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Unit 2 Lesson 1 Introduction to Energy
What are two types of energy?
• Potential energy is the 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.
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Unit 2 Lesson 1 Introduction to Energy
What are two types of energy?
• A change in the condition of an object affects its
potential energy. Stretching a rubber band
increases its 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.
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Unit 2 Lesson 1 Introduction to Energy
Can objects have potential and kinetic
energy at the same time?
• An object can have both potential and kinetic
energy at the same time.
• A skater has kinetic energy as he moves down a
ramp and potential energy due to his position on
the ramp.
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Unit 2 Lesson 1 Introduction to Energy
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.
• Some common forms of energy include
mechanical, sound, electromagnetic, electrical,
chemical, thermal, and nuclear energy.
• Energy is expressed in joules (J).
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Unit 2 Lesson 1 Introduction to Energy
What forms can energy take?
• Mechanical energy is the sum of an object’s
kinetic energy and potential energy. It is the
energy of position and motion.
• Sound energy is kinetic energy caused by the
vibration of particles in a medium such as steel,
water, or air.
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Unit 2 Lesson 1 Introduction to Energy
What forms can energy take?
• Electromagnetic energy is transmitted through
space in the form of electromagnetic waves.
• These waves are caused by the vibration of
electrically charged particles.
• Electromagnetic waves include visible light, Xrays, and microwaves.
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Unit 2 Lesson 1 Introduction to Energy
What forms can energy take?
• Electrical energy is the energy that results from
the position or motion of charged particles.
• Chemical energy is a form of potential energy.
• The amount of chemical energy in a molecule
depends on the kinds of atoms and their
arrangement.
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Unit 2 Lesson 1 Introduction to Energy
What forms can energy take?
• The thermal energy of an object is the kinetic
energy of its particles.
• The faster the molecules in an object move, and
the more particles the object has, the more
thermal energy it has.
• Heat is the energy transferred from an object at a
higher temperature to an object at a lower
temperature.
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Unit 2 Lesson 1 Introduction to Energy
What forms can energy take?
• The nucleus of an atom is the source of nuclear
energy.
• When an atom’s nucleus breaks apart, or when
the nuclei of two small atoms join together,
energy is released.
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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.
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Unit 2 Lesson 1 Introduction to Energy
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.
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Unit 2 Lesson 1 Introduction to Energy
What is an energy transformation?
• In a flashlight, chemical energy is transformed
into electrical energy.
• The electrical energy is then transformed into light
and thermal energy.
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Unit 2 Lesson 1 Introduction to Energy
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.
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Unit 2 Lesson 2 Temperature
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Unit 2 Lesson 2 Temperature
Particle Party
What is the kinetic theory of matter?
• The kinetic theory of matter states that all of
the particles that make up matter are constantly
in motion.
• Because the particles are in motion, they have
kinetic energy.
• The faster they move, the more kinetic energy
they have.
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Unit 2 Lesson 2 Temperature
What is the kinetic theory of matter?
• The motion of the particles is random.
• The individual particles have different amounts of
kinetic energy, but their average kinetic energy
takes into account their different random motions.
• Solids, liquids, and gases have different average
kinetic energies.
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Unit 2 Lesson 2 Temperature
How do particles move in solids,
liquids, and gases?
• The kinetic theory of matter explains the motion
of particles in solids, liquids, and gases.
• The particles in a solid do not move around much.
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Unit 2 Lesson 2 Temperature
How do particles move in solids,
liquids, and gases?
• The particles in a liquid move much more freely
than the particles in a solid. They slide past and
tumble over each other.
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Unit 2 Lesson 2 Temperature
How do particles move in solids,
liquids, and gases?
• The particles in a gas are far apart, move at high
speeds, and collide with one another.
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Unit 2 Lesson 2 Temperature
Mercury Rising
How does temperature relate to kinetic
energy?
• Temperature is a measure of the average kinetic
energy of all the particles in an object.
• The warmer a substance is, the faster its particles
move.
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Unit 2 Lesson 2 Temperature
How is temperature measured?
• There are three common temperature scales.
• They all measure the average kinetic energy of
particles.
• The scales are called Celsius, Fahrenheit, and
Kelvin.
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Unit 2 Lesson 2 Temperature
How is temperature measured?
• In the Celsius and Fahrenheit scales, temperature
is measured in units called degrees.
• Degrees (°) are equally spaced units between
two points. The space between degrees can vary
from one scale to another.
• In the Kelvin scale, no degree sign is used. The
unit is just called a kelvin.
• Temperature is measured with a thermometer.
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Unit 2 Lesson 2 Temperature
How is temperature measured?
• The Celsius scale is the temperature scale most
commonly used around the world.
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Unit 2 Lesson 2 Temperature
How is temperature measured?
• The Fahrenheit scale is used most commonly in
the United States.
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Unit 2 Lesson 2 Temperature
How is temperature measured?
• The Kelvin scale is used most commonly by
physicists.
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