energy transfer a

7/28/2019 Energy Transfer A

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Energy TransferSyllabus

Title Page

Lesson 01 Types of Energy

Lesson 02 Energy Efficiency

Lesson 03 Conduction and ConvectionLesson 04 Radiation and Insulation

Lesson 05 Insulating Homes


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Energy


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Energy Transfers 09/07/2013Aim:

To define energy

To explain the purpose of a transducer and their role inthe conservation of energy

To identify energy transfers

Starter: in rough

Write down words / phrases about energy

Compare with your neighbour

Compare with your table Agree a definition of energy and one of you write it

down (can be more than one sentence)


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EnergyDefinition:

Energy is required to do anything (work) (e.g. heat up).

Energy is always conserved, it is never used up or destroyed it istransferred into another form (e.g. chemical to heat and light).

A transducer changes energy from one form to another (e.g. amatch).

Symbol: E

Unit: J (joules)

Analogy:

Energy is like money.

To do anything costs money. Money is not used up but changes hands when you pay for

something.

Handout Demo Burning Ethanol
http://localhost/var/www/apps/conversion/tmp/scratch_14/Energy%20-%20Transfer%20-%2001%20-%20Handout%20Energy%20Types.docxhttp://localhost/var/www/apps/conversion/tmp/scratch_14/Energy%20-%20Transfer%20-%2001%20-%20Handout%20Energy%20Types.docxhttp://localhost/var/www/apps/conversion/tmp/scratch_14/Energy%20-%20Transfer%20-%2001%20-%20Handout%20Energy%20Types.docx


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Types of energy There are two groups of energy and nine types you need

to learn

In rough write down what types of energy you can thinkof in 1 minute(think about the burning ethanol demo)


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Types of Energy

Electrical energy

ACTIVE (KINETIC) ENERGY STORED (POTENTIAL) ENERGY


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Types of Energy _________ _______ (KE) are all types of movement energy.

_________ _______ (PE) are all types of stored energy.

Type KE or PE? Example Sources

Kinetic (movement)

Heat (thermal) KE flame

Light

Gravitational

Chemical

Sound

Electrical

Elastic

Nuclear

Kids Hate Learning GCSEEnergy Names



On your white board write down the type of energy

1. Energy in a toffee

2. Energy in a running girl

3. Energy causing a light bulb to light

4. Energy given off by a stationary boy

5. Energy in music

6. Energy in a spring shot

7. Energy in a diver



Energy TransfersWatch the demo (flour fire breathing)

What energy transfers are occurring?



Example Energy Transfers?

electrical kinetic

kinetic electricalelectrical sound

light chemical



There can be more than one step

More Complicated Examples

gravitational potential

kinetic

electrical

Energy can be transferred into more than one type

electrical

light

heat sound



Energy Circus Around the lab are a selection of transducers.

For each one identify

All the energy transfers (every stage) Underline useful transfers

Bracket wasted transfers

Write the name and transfers into your books

Example (try in your books in pencil)

1. Catapult Girl

Chemical kinetic kinetic

(heat)

elastic

gravitational

(heat)

(sound)

Elastic
http://localhost/var/www/apps/conversion/tmp/scratch_14/Energy%20-%20Transfer%20-%2001%20-%20Movie%20Girl%20in%20Human%20Slingshot.avihttp://localhost/var/www/apps/conversion/tmp/scratch_14/Energy%20-%20Transfer%20-%2001%20-%20Movie%20Girl%20in%20Human%20Slingshot.avi



Identifying energy transfers



Energy Transfers recapAim:

To define a energy

To explain the purpose of a transducer and their role inthe conservation of energy

To identify energy transfers

Plenary: on whiteboards

Write down the two most important things you havelearnt this lesson.



Efficiency 09/07/2013Aim: To create sankey diagrams To calculate efficiency

Starter: Watch the Movie (Roller Coaster) Identify the energy transfers How is energy wasted?
http://localhost/var/www/apps/conversion/tmp/scratch_14/Energy%20-%20Transfer%20-%2002%20-%20Movie%20Goliath%20Roller%20Coaster.flvhttp://localhost/var/www/apps/conversion/tmp/scratch_14/Energy%20-%20Transfer%20-%2002%20-%20Movie%20Goliath%20Roller%20Coaster.flv



Wasted sound energyIf you can hear a device that is not designed to make noise then energy iswasted as sound.

Examples of devices that waste energy as sound include:



Wasted Heat EnergyIf a device gets warm and it is not designed to get warm then energy iswasted as heat.

Examples of devices that waste energy as heat include:



Which Type of Energy is Wasted?



Wasted Energy Energy is normally wasted as heat and sound

Wasted energy dissipates (spreads out) into the

surroundings. This dissipated energy is too spread out to do useful

work and so cannot be re-used.

S k Di A C dl



Sankey Diagram A Candle


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Sankey Diagram A Candle

Energy in: Every second the candle transfers 100 joules of chemical energy

Energy out: 20 joules into light energy and 80 joules into heat energy

100 J

electricalenergy

Input energy Output energy

80 J heat energy

20 J light energy

So each block represents 10J

Only the width matters not the length


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Sankey Diagram Running Man

k


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heat energy

sound energy

kineticenergy

2000 Jelectricalenergy

Sankey Diagram - Running Man Energy in: Every second the man transfers 2000 J of chemical energy

Energy out: ? of useful kinetic, ? of useful sound, ? of wasted heat

So each block represents 200 J


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Questions

Draw Sankey diagrams for the following on graph paper.

Highlight the useful energy.

Leave the right hand side of the graph paper empty.1. Light Bulb

input: Electrical 200J

output: Light 30J, Heat ?J

2. Fire

input: Chemical 200J

output: Heat 150J, Light ?J and Sound 20J

3. Drill


output: Kinetic 300J, Sound 200J, Heat ?J4. Computer

input: Electrical ?J

output: Sound 50J, Light 100J, Heat 80J and Kinetic 20J


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Questions

Make Sankey diagrams for the following on graph paper.

Highlight the useful energy.

Leave the right hand side of the graph paper empty.1. Light Bulb


output: Light 30J, Heat 170J

2. Fire


output: Heat 150J, Light 30J and Sound 20J

3. Drill


output: Kinetic 300J, Sound 200J, Heat 500J4. Computer



E Effi i


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Energy Efficiency

Definition:

The amount of energy transferred usefully.

Can never exceed 1 or 100%.

Equation:

Efficiency = useful energy out

total energy in It has no Units

It can be a %

E l


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Example A TV Supplies 50J of heat energy, 50J of sound energy,

and 100J of light energy.

a) What is the useful energy out?

b) What is the total energy in?

c) Calculate the efficiency of the TV?

Whit b d Q ti


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Whiteboard Questions

Q ti


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Questions

a) What is the useful energy out?

b) What is the input energy in?

c) Calculate is the efficiency?1. Light Bulb


output: Light 30J, Heat 170J

2. Fire


output: Heat 150J, Light 30J and Sound 20J

3. Drill


output: Kinetic 300J, Sound 200J, Heat 500J4. Computer



1) Li ht B lb


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Electrical(total in) Heat(wasted)

Light(useful)

200 J 170J

30J

a) useful energy out = 30Jb) total energy in = 200Jc) Efficiency = useful

total= 30200

= 0.15 or 15%

1) Light Bulb

2) Fi


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Chemical(total in)

Heat(useful)

sound(wasted)

200 J

150J

20J

a) useful energy out = 150 + 30= 180 J

b) total energy in = 200 Jc) Efficiency = useful

total= 180

200= 0.9 or 90%

2) Fire

Light(useful)

30J

3) D ill


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Electrical(total in)

Kinetic(useful)

Heat(wasted)

1000 J

300J

500J


total

= 3001000

= 0.3 or 30%

3) Drill

Sound(wasted)

200J

4) C mp t


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Electrical(total in)

Sound(useful)

Heat(wasted)

250 J

50J

80J


total

= 170250

= 0.68 or 68%

4) Computer

Light(useful)

100J

Kinetic(useful)

20J

Multiple ch ice quiz


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Multiple-choice quiz

Anagrams


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Anagrams

Efficiency recap


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Efficiency recapAim: To create sankey diagrams

To calculate efficiency

energy transfer a

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