There’s no two ways about it, the story we used to have on energy was bad. Inconsistency, incoherence, subjectivity: words to send a shiver down the spines of any scientist. Something had to change. The response from IOP was the ‘stores’ and ‘pathways’ model. This was championed by our podcast guest this evening. Thomas and Robin are honoured to welcome Charles Tracy (@charlesmtracy) of the IOP about how to introduce Energy to 11 year olds.

Charles did so much to champion the new model of energy, tirelessly convincing educators, exam boards and textbook manufacturers that the new way was consistent and straightforward and gave students a much better account of this essentially abstract quantity.

If you are introducing energy at KS3 you face an immediate challenges: energy is all about calculation and of course there are no calculations until KS4. That said, Charles tells us that we can think about energy conservation and talk about how much is in a particular store without calculating.

An important consideration is defining your start and end points for your consideration of the transfer between stores. A bouncing ball may go through any number of transfers between stores over the course of a few bounces, but defining your ‘start’ as just before the ball is released and your ‘end point’ as just before it first bounces, means you can talk specifically about the specific transfer between the gravitational store and the kinetic store.

To help you frame the start and end points Charles explains how it is important to have a calculation you could perform in your mind when designing an experiment. (eg. “How much kinetic energy does the ball have at the start and the end?”) You don’t need that for most year 11 year olds but it certainly comes in when you revisit Energy in the run up to GCSEs (Exams for 16 year olds in the UK).

Listen close to Charles’s descriptions: the elegance and clarity of the model comes through. Charles has promised to return to talk energy at KS4 – we could listen to him all day!

Charles wanted to add:

It is helpful to look at phenomena using these three steps:

1. Description – of what you observe and what is happening
2. Explanation in terms of mechanisms and processes; changes that occur due to forces, differences in temperature, chemical reactions etc.
3. Energy analysis – based on start and end points.

Something I would draw out for part 3 is that you should not try to mirror or reproduce the mechanisms and processes in the energy analysis. The energy analysis performs a completely different task – based on solely the start and end points.

Links

• Our previous episode: The ” New” Model of Energy
• Teaching Secondary Physics Text Book (amazon or Millgate House)
• “Swinging Ball of Death” – Big Pendulum
• 9 Blogs from IoP about the New Energy Curriculu
• IoP Spark Questions about Energy (also available for download as a pdf)

Join in!

Please share ideas or successes – or indeed questions – on our Facebook Page: https://fb.me/physicstp .  You can also message us via our website contact form at the.physicsteachingpodcast.com, Twitter @physicstp, email using  the address given in the podcast (if we remember), you could even email us an autio file if you are feeling really keen.

Music

• Season 7: Physics Is Our Business by Miracles of Modern Science.
• Seasons 5 and 6: Crescents by Ketsa.
• Seasons 3 and 4: Disco Sheik by Podington Bear.
• Seasons 1 and 2: One legged equilibrist polka by Circus Homunculus.
• Occasionally we also use Cantina Rag by Jackson F. Smith.

The music is used under the Attribution-NonCommercial 3.0 International License