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Work in progress. Teaching energy Gary Williams. 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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Work in progress Teaching energy Gary Williams Liverpool Physics Teachers Conference 2004
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. Liverpool Physics Teachers Conference 2004
The problem • Energy doesn’t exist, it’s a mathematical “quantity” • The concept of energy is a powerful tool for showing equivalence between systems • There’s a lot of new language on the way to understanding • It’s in exams Liverpool Physics Teachers Conference 2004
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 Liverpool Physics Teachers Conference 2004
Boohan and Ogborn – Energy and change Liverpool Physics Teachers Conference 2004
Nuclear Gravitational potential Internal Elastic potential Chemical The CCB Energy approach • Kinetic • Heating • Sound • Radiation • Electrical work Liverpool Physics Teachers Conference 2004
The big picture – a system Transformer Energy sink Energy source Liverpool Physics Teachers Conference 2004
A power station – a source Chemical Electrical work Liverpool Physics Teachers Conference 2004
A light bulb – a transformer Lamp Liverpool Physics Teachers Conference 2004
Lifting a weight – a sink Liverpool Physics Teachers Conference 2004
A try this example • The stereo runs off mains electricity • The device converts the energy • The energy goes where? • Into the environment. Liverpool Physics Teachers Conference 2004
Mains electricity comes from power stations Liverpool Physics Teachers Conference 2004
Stereo The stereo is just like a loudspeaker Liverpool Physics Teachers Conference 2004
The sound goes into the environment Liverpool Physics Teachers Conference 2004
Stereo Liverpool Physics Teachers Conference 2004
Stereo Write the word descriptions under the symbols Liverpool Physics Teachers Conference 2004
We had: Lamp So where’s the heating? Liverpool Physics Teachers Conference 2004
A normal light bulb is only about 10%EFFICIENT. Liverpool Physics Teachers Conference 2004
Lets draw it like this: Lamp 90% 10% Then we know what’s going where. Liverpool Physics Teachers Conference 2004
Motor 65% 30% 5% Liverpool Physics Teachers Conference 2004
So a power station would look like: Boiler Turbine Generator 30% 70% 50% 15% 20% 15% 10% 5% 5% Liverpool Physics Teachers Conference 2004
Most power stations are very similar: Turbine A turbine changes kinetic energy so that it’s more useful Liverpool Physics Teachers Conference 2004
A generator converts kinetic energy into electrical work Generator Then the electricity gets sent to your home. Liverpool Physics Teachers Conference 2004
Hydroelectricity Turbine Generator Falling water turns a turbine which drives a generator Liverpool Physics Teachers Conference 2004
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. Liverpool Physics Teachers Conference 2004
Heating Radiation Radiation Electrical work Electrical work Sound Sound 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 Liverpool Physics Teachers Conference 2004
Why does it work? • It’s very visual • Pupils don’t need to know the language straight away • It’s very interactive Liverpool Physics Teachers Conference 2004
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 Liverpool Physics Teachers Conference 2004
Where should we go? • Banish all forms of energy that don’t have equations at GCSE? • Reduce the forms of energy to 4 – the same as the number of fundamental forces? (or 3?) Liverpool Physics Teachers Conference 2004
All the resources can be downloaded from the Christ College website: http://www.christcollegebrecon.com/ From the menu follow: Academic>>>subject list>>>>Physics Liverpool Physics Teachers Conference 2004