Liverpool Physics Teachers Conference 2004 25 July 2019 Liverpool Physics Teachers Conference 2004

Teaching energy Gary Williams Work in progress Teaching energy Gary Williams This talk is based on a paper that Tony Reeves and I wrote about work that we’d done at Christ College, Brecon. 25 July 2019 Liverpool Physics Teachers Conference 2004

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. 25 July 2019 Liverpool Physics Teachers Conference 2004

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 25 July 2019 Liverpool Physics Teachers Conference 2004

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 25 July 2019 Liverpool Physics Teachers Conference 2004

Boohan and Ogborn – Energy and change 25 July 2019 Liverpool Physics Teachers Conference 2004

The CCB Energy approach Nuclear Gravitational potential Internal Elastic potential Chemical Kinetic Heating Sound Radiation Electrical work The idea was based on the Boohan-Ogborn energy diagrams in the ASE project “energy and change” 25 July 2019 Liverpool Physics Teachers Conference 2004

The big picture – a system Transformer Energy sink Energy source 25 July 2019 Liverpool Physics Teachers Conference 2004

A power station – a source Chemical Electrical work 25 July 2019 Liverpool Physics Teachers Conference 2004

A light bulb – a transformer Lamp 25 July 2019 Liverpool Physics Teachers Conference 2004

Lifting a weight – a sink 25 July 2019 Liverpool Physics Teachers Conference 2004

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. 25 July 2019 Liverpool Physics Teachers Conference 2004

Liverpool Physics Teachers Conference 2004 Mains electricity comes from power stations 25 July 2019 Liverpool Physics Teachers Conference 2004

Liverpool Physics Teachers Conference 2004 Stereo The stereo is just like a loudspeaker 25 July 2019 Liverpool Physics Teachers Conference 2004

Liverpool Physics Teachers Conference 2004 The sound goes into the environment 25 July 2019 Liverpool Physics Teachers Conference 2004

Liverpool Physics Teachers Conference 2004 Stereo 25 July 2019 Liverpool Physics Teachers Conference 2004

Liverpool Physics Teachers Conference 2004 Stereo Write the word descriptions under the symbols 25 July 2019 Liverpool Physics Teachers Conference 2004

Liverpool Physics Teachers Conference 2004 We had: Lamp So where’s the heating? 25 July 2019 Liverpool Physics Teachers Conference 2004

A normal light bulb is only about 10% EFFICIENT. 25 July 2019 Liverpool Physics Teachers Conference 2004

Liverpool Physics Teachers Conference 2004 Lets draw it like this: Lamp 90% 10% Then we know what’s going where. 25 July 2019 Liverpool Physics Teachers Conference 2004

Liverpool Physics Teachers Conference 2004 Motor 65% 30% 5% 25 July 2019 Liverpool Physics Teachers Conference 2004

So a power station would look like: Boiler Turbine Generator 30% 70% 50% 15% 20% 15% 10% 5% 5% 25 July 2019 Liverpool Physics Teachers Conference 2004

Liverpool Physics Teachers Conference 2004 25 July 2019 Liverpool Physics Teachers Conference 2004

Most power stations are very similar: Turbine A turbine changes kinetic energy so that it’s more useful 25 July 2019 Liverpool Physics Teachers Conference 2004

A generator converts kinetic energy into electrical work Then the electricity gets sent to your home. 25 July 2019 Liverpool Physics Teachers Conference 2004

Liverpool Physics Teachers Conference 2004 Hydroelectricity Turbine Generator Falling water turns a turbine which drives a generator 25 July 2019 Liverpool Physics Teachers Conference 2004

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. 25 July 2019 Liverpool Physics Teachers Conference 2004

Liverpool Physics Teachers Conference 2004 25 July 2019 Liverpool Physics Teachers Conference 2004

Liverpool Physics Teachers Conference 2004 10. Which boxes best show the useful energy transfer which takes place in an electric bell? A B Electric Bell Radiation Sound Electric Bell Electrical work Kinetic D C Electric Bell Electric Bell Electrical work Sound Heating Radiation 25 July 2019 Liverpool Physics Teachers Conference 2004

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 25 July 2019 Liverpool Physics Teachers Conference 2004

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 25 July 2019 Liverpool Physics Teachers Conference 2004

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?) 25 July 2019 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 25 July 2019 Liverpool Physics Teachers Conference 2004