energy. energy: forms and changes nature of energy energy is all around you! –y–you can hear...
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Energy
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.
Nature of Energy
• You use energy when you:– hit a softball.– lift your book bag.– compress a
spring.
Nature of Energy
Living organisms need energy for growth and movement.
Nature of Energy
• Energy is involved when:– a bird flies.– a bomb explodes.– rain falls from the sky.– electricity flows in a
wire.
Energythe ability to do work
Energy comes in many forms:mechanical, electrical , magnetic, solar,
thermal, chemical, etc...
The SI unit of energy is the Joule.
Energy
Energy
Potential EnergyStored energy and the
energy of position
Kinetic EnergyMotion of waves, electrons,
atoms, molecules, and substances
Potential EnergyStored energy and the
energy of position
Chemical EnergyEnergy stored in the bonds of
atoms and molecules
Elastic EnergyEnergy stored in objects by the
application of force.
Nuclear EnergyEnergy stored in the nucleus of an atom – the energy that holds the
nucleus together
Gravitational EnergyEnergy of place or position
Potential EnergyStored energy and the
energy of position
Kinetic EnergyMotion of waves, electrons, atoms, molecules, and
substances
Kinetic EnergyMotion of waves, electrons, atoms, molecules, and
substancesElectrical
EnergyMovement of
electrons
Mechanical MotionMovement of substance from
one place to another
Sound EnergyMovement of energy through substances in longitudinal waves
Radiant EnergyElectromagnetic energy that travels in transverse waves
Thermal EnergyInternal energy in substances – vibration or movement of atoms and molecules in
substancesa.k.a. “heat”
Potential EnergyStored Energy
gravitational potential energy
GPE = mgh m - mass of object in kg g - acceleration of gravity in m/s2
h - height of object, in m, GPE – gravitational potential energy in J
Kinetic Energyenergy of motion
All moving objects thathave mass have kinetic energy.
KE = 1/2 mv2
m - mass of the object in kgv - speed of the object in m/sKE - the kinetic energy in J
Different Types of Energy.
Kinetic Energy
Anything that moves has kinetic energy.
Gravitational Potential Energy (GPE)Anything above the ground has gravitational potential energy i.e. anything that can fall, like ski jumpers, aeroplanes and climbers.
Nuclear Energy
Released only from nuclear reactions The sun and all of the stars. Hydrogen bomb (Fusion)Nuclear power plants
Sound EnergyAnything noisy gives off sound energy like vocal chords, speakers and instruments.
Chemical Energy
Anything with stored energy which can be released by a chemical reaction has chemical energy, things like food fuels and batteries.
Radiant Energyalso called electromagnetic energy
All life on Earth depends upon radiant energy from the sunExamples: radio waves, microwaves, X-rays,
Heat/Thermal Energy
Anything with a temperature above absolute zero (-273°C) has heat energy. That means everything has some thermal energy.
Light EnergyAnything luminous gives off light energy, like the sun, light bulbs , candles and glow worms.
Electrical Energy
Electrical energy is very useful, because its easily converted into other forms – wherever there's a current flowing there's electrical energy.
Elastic Energy Anything stretched, has elastic energy – things like rubber bands, springs, knickers, elastic etc
There are 9 types of energy hidden in this pictureCan you find them?
Can you think of examples of each type of energy?
There are many different types of energy:
thermallightsoundelasticgravitationalkineticelectricalchemicalnuclear
Different types of energy
Which type of energy?
Energy can be changed from one form to another.
For example:Chemical energy in food is
converted to thermal energy and kinetic energy by our bodies.
Energy transfer
What other energy transfers can you think of?
Gravitational energy in a ball is converted to kinetic energy when it falls to the ground.
burning match portable torch microphone radio television catapult mobile phone
car
Describe energy transfer in each device
burning match portable torch microphone radio television catapult mobile phone
car
chemical to thermal and lightchemical to thermal and lightsound to electricalelectrical to sound and thermalelectrical to sound and light and thermalelastic to kinetic and thermalchemical to sound and microwaves(EM radiation) and thermalchemical to kinetic and sound and thermal
In all these transfers the energy is not lost, it is conserved. Energy cannot be destroyed or created.
Describe energy transfer in each device
Draw an energy transfer for... YOU!!
ChemicalHeat
Kinetic (movement)
Sound
Energythe ability to do work
Energy comes in many forms:mechanical, electrical , magnetic, solar,
thermal, chemical, etc...
The SI unit of energy is the Joule.
Energy
Energy
Potential EnergyStored energy and the
energy of position
Kinetic EnergyMotion of waves, electrons,
atoms, molecules, and substances
Potential EnergyStored energy and the
energy of position
Chemical EnergyEnergy stored in the bonds of
atoms and molecules
Elastic EnergyEnergy stored in objects by the
application of force.
Nuclear EnergyEnergy stored in the nucleus of an atom – the energy that holds the
nucleus together
Gravitational EnergyEnergy of place or position
Potential EnergyStored energy and the
energy of position
Kinetic EnergyMotion of waves, electrons, atoms, molecules, and
substances
Kinetic EnergyMotion of waves, electrons, atoms, molecules, and
substancesElectrical
EnergyMovement of
electrons
Mechanical MotionMovement of substance from
one place to another
Sound EnergyMovement of energy through substances in longitudinal waves
Radiant EnergyElectromagnetic energy that travels in transverse waves
Thermal EnergyInternal energy in substances – vibration or movement of atoms and molecules in
substancesa.k.a. “heat”
Potential EnergyStored Energy
gravitational potential energy
GPE = mgh m - mass of object in kg g - acceleration of gravity in m/s2
h - height of object, in m, GPE – gravitational potential energy in J
Potential EnergyStored Energy
gravitational potential energy
GPE = Wh W – Weight of object in N h - height of object, in m, GPE – gravitational potential energy in J
Roller Coaster Conversions
The NEED Project
The NEED Project
Energy pokerLook at the scenes on the slides that follow. Make a bid for the number of energy transfers that you can see. The person with the highest bid has to explain where they are. If they fail to find that number they lose.Can you win at energy poker?
Let’s look at a couple of examples first…
First Example…
Energy poker score: 1Sunlight energy converted into heat to boil the water for tea
Energy poker score: 3Chemical energy in fuel converted to movement, heat and sound
Second Example…
Now for the real thing… make a bid for the number of energy transfers that you can see!
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