Work in progress

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Work in progress

• Teaching energy
• Gary Williams

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Historically

• UK physics teaching has become more conceptual
• Nuffield introduced the ideas of different labels
  sound energy, food energy etc
• This idea has been taken too far
• We have reinforced the idea of caloric rather
  than destroying it.

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The problem

• Energy doesnt exist, its a mathematical
  quantity
• The concept of energy is a powerful tool for
  showing equivalence between systems
• Theres a lot of new language on the way to
  understanding
• Its in exams

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A solution

• Should start where we are now
• Should finish where we want to be
• Must tackle the language problem
• Must highlight the underlying mathematical nature
  of energy
• Needs to address likely exam questions

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Boohan and Ogborn Energy and change
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The CCB Energy approach

• Nuclear
• Gravitational potential
• Internal
• Elastic potential
• Chemical

• Kinetic
• Heating
• Sound
• Radiation
• Electrical work

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The big picture a system
Transformer
Energy sink
Energy source
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A power station a source
Chemical
Electrical work
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A light bulb a transformer
Lamp
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Lifting a weight a sink
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A try this example

• The stereo runs off mains electricity
• The device converts the energy
• The energy goes where?
• Into the environment.

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Mains electricity comes from power stations
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Stereo
The stereo is just like a loudspeaker
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The sound goes into the environment
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Stereo
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Stereo
Write the word descriptions under the symbols
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We had
Lamp
So wheres the heating?
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A normal light bulb is only about 10EFFICIENT.
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Lets draw it like this
Lamp
90
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Then we know whats going where.
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Motor
65
30
5
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So a power station would look like
Boiler
Generator
Turbine
30
50
70
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15
20
10
5
5
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Most power stations are very similar
Turbine
A turbine changes kinetic energy so that its
more useful
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A generator converts kinetic energy into
electrical work
Generator
Then the electricity gets sent to your home.
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Hydroelectricity
Generator
Turbine
Falling water turns a turbine which drives a
generator
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The Elan Valley scheme in the Cambrian Mountains
of mid-Wales comprises five reservoirs and four
dams, built between the end of the 19th century
and 1952. The reservoirs hold 199 million tonnes
of water and are the main water supply source for
Birmingham.
During the 1990s, the existing water supply was
harnessed to generate electricity. The scheme
generates power to meet the needs of nearly
11,000 homes, avoiding carbon dioxide (CO2)
emissions of 26,200 tonnes a year.
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10. Which boxes best show the useful energy
transfer which takes place in an electric bell?
A
B
ElectricBell
ElectricBell
Kinetic
D
C
ElectricBell
ElectricBell
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Why does it work?

• Its very visual
• Pupils dont need to know the language straight
  away
• Its very interactive

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Why did we do it?

• The teaching of energy needs some common ground
• Our teaching of this subject needs to improve
• Too often pupils in the past have little long
  term recall of this topic

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Where should we go?

• Banish all forms of energy that dont have
  equations at GCSE?
• Reduce the forms of energy to 4 the same as the
  number of fundamental forces? (or 3?)

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All the resources can be downloaded from the
Christ College website
http//www.christcollegebrecon.com/
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