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Week#24, 2012-13 Energy Unit Today

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Wednesday, Feb. 27

ESSENTIAL QUESTION

EQ: What is energy? My Answer(Class work AND homework):

Homework► Homework for Friday: Vocabulary. Homework for tomorrow: Proofread EQ answer.

Announcements, Questions???, Review A, Q, R Students’ Objective Obj. 6.P.3 To understand energy

Quotation to relate to science or life

“To the uneducated, an A is just three sticks.”—A. A. Milne

Teacher presents. Energy introduction—ppt and smartboard notebook Students do. Energy Guided Notes

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What does this mean?

• 70, 100, 90, 60, 100, 70, 100, 90, 60, 100

• 84• 70, 100, 0, 60, 100, 70, 100, 90, 60, 0

• 65• 70, 100, 0, 60, 100, 0, 0, 90, 60, 0

• 48• 0, 100, 0, 0, 100, 0, 0, 0, 60, 0

• 26

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What happens when you reverse it?

• 0, 100, 0, 0, 100, 0, 0, 0, 60, 0 • 26

• 70, 100, 0, 60, 100, 0, 0, 90, 60, 0 • 48

• 70, 100, 0, 60, 100, 70, 100, 90, 60, 0 • 65

• 70, 100, 90, 60, 100, 70, 100, 90, 60, 100

• 84

• 84 !

EnergyWhat is energy?

What forms does energy come in?

Does energy get used up?

Can energy change from one type to another?

These are the questions we will answer.You will be required to complete the accompanying Energy ppt Guided Notes.

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What is Energy?

The ability to do work on an object or cause change to an object.

• This means you need to know what work is. In physical science, work is a math concept.

• work = force x distance• That means work is pushing or

pulling an object and causing it to move.

So energy is the ability to do this type of work.

As a class, let’s come up with some examples:

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What are the different forms of energy?

• Energy has different forms, all of which measure the ability of an object to do work on or change another object.

• In other words, there are different ways that an object can possess energy.

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What are 8 different forms of Energy?

• Kinetic Energy• Potential Energy2. Thermal energy (heat energy)3. Chemical Energy4. Electrical Energy5. Electrochemical Energy6. Electromagnetic Energy (e.g. light)7. Sound Energy8. Nuclear Energy* PE and KE are usually used with mechanical energy.

1.Mechanical Energy*

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Define Potential Energy

• Potential energy is energy of an object due to its position or shape. – A special type of potential energy is

gravitational potential energy.• Let’s come up with an example of

potential energy that is not gravitational:

• Let’s come up with an example of gravitational potential energy:

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Two examples of potential energy

By stretching a rubber band, you give it potential energy because of its shape.

A vase on a shelf has gravitational potential energy because of its position.

So gravitational potential energy is due to an object’s height.

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Define Kinetic Energy

Kinetic energy is the energy of motion.

Kinetic energy is measured by how much work is done to start or stop an object’s motion.

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Examples of kinetic energy

A basketball player has kinetic energy.

Her movements show kinetic energy.

When you are running, walking, or jumping, your body is exhibiting kinetic energy.

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Can you give an example of something that has both

potential and kinetic energy? Here is one.

A waterfall has both kinetic and potential energy. The water at the top of the waterfall has stored potential energy. Once the water leaves the top of the waterfall, the potential energy is changing into kinetic energy.

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Describe Conservation of Energy

Energy cannot be created or destroyed; it can only be changed from one of form of energy to another form. 

The amount of energy stays the same. 

This answers two questions shown earlier:• Does energy get used up?• Can energy change from one type to another?

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Describe Conservation of EnergyClick here for more examples of

Conservation of Energy:

http://web.singnet.com.sg/~stepchin/Conserv.htm

Remember that you might have to hit the “back” button on your browser to return

to this slide show.

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more about P.E.– Potential energy: Stored energy that

results from the position or shape of an object.• Gravitational potential energy:

Potential energy related to an object’s height.– Gravitational potential energy =

weight X height

• Elastic potential energy: The potential energy of objects that can be stretched or compressed.

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More forms of energy

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Forms of Energy• Electromagnetic• Thermal• Sound• Mechanical• Electrical• Nuclear• Chemical

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Forms of Energy• This is a graph of what type of energy?

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Forms of Energy• Electromagnetic: Energy that is caused

by the acceleration of charged particles.• Thermal: The total of the potential and

kinetic energy of the particles in an object.

• Sound: The energy produced by an object’s vibration.

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Forms of Energy

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Forms of Energy

• Mechanical: The form of energy that is associated with the position and motion of an object; can be potential or kinetic.

• Electrical: The energy of electrical charges; can be potential or kinetic.

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What are some types of energy?

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Forms of energy

• Nuclear: A type of potential energy that is stored in the nucleus of an atom.– Nuclear fission: The splitting of a

nucleus.– Nuclear fusion: The fusing of two

separate nuclei into one nucleus.

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Forms of energy• Chemical: Potential energy that is stored

in the chemical bonds that hold chemical compounds together.– Food is chemical energy. Our bodies are

chemical energy.

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Can energy change from one form to another?

• To answer, explain the next slide.

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EN

ER

GY

T

RA

NS

FO

RM

AT

ION

SNuclear

electromagnetic

chemical

mechanical (movement)

thermal (body temperature)

electrical (brain)

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Main Idea—Conservation of Energy

• What was the main idea from this presentation?– Energy is not created or destroyed, it

just changes from one form to another.

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The

• end

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New, related topic

•Averages•Extra Credit

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Science

• can be difficult,• but it doesn’t have to be.• It is your choice.

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What does this mean?

• 70, 100, 90, 60, 100, 70, 100, 90, 60, 100

• 84• 70, 100, 0, 60, 100, 70, 100, 90, 60, 0

• 65• 70, 100, 0, 60, 100, 0, 0, 90, 60, 0

• 48• 0, 100, 0, 0, 100, 0, 0, 0, 60, 0

• 26

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What happens when you reverse it?

• 0, 100, 0, 0, 100, 0, 0, 0, 60, 0 • 26

• 70, 100, 0, 60, 100, 0, 0, 90, 60, 0 • 48

• 70, 100, 0, 60, 100, 70, 100, 90, 60, 0 • 65

• 70, 100, 90, 60, 100, 70, 100, 90, 60, 100

• 84

• 84 !

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EXTRA SLIDES, NOT PART OF PRESENTATION:

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#2 Let’s get started on your paper. Write your heading

Let’s titlethis.

Notes – Physical Properties

Now here’s the important part. To makethis set of notes useful to you, it has tobe neat & organized.

I’ll make anythingyou need to write on your paper in red text,like I did with the title up there. Got it?

Let’s get started here.