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Calculating energy everywhere - Teaching approaches
Total Energy of a System
Energy and Thermal Physics
Calculating energy everywhere - Teaching approaches
Classroom Activity for 11-14
A Teaching Approach is both a source of advice and an activity that respects both the physics narrative and the teaching and learning issues for a topic.
The following set of resources is not an exhaustive selection, rather it seeks to exemplify. In general there are already many activities available online; you'll want to select from these wisely, and to assemble and evolve your own repertoire that is matched to the needs of your class and the equipment/resources to hand. We hope that the collection here will enable you to think about your own selection process, considering both the physics narrative and the topic-specific teaching and learning issues.
What the Activity is for
The purpose of this activity is to introduce the conventions of, and pupils to acquire familiarity with, Sankey diagrams. These diagrams allow us to describe processes in terms of the rates at which energy is shifting down various pathways. Ultimately this will require calculations, but for now estimates are enough to get the conversations started. The interactive object allows you to build Sankey diagrams for a number of given situations, and then to construct your own.
There is an important choice to be made: you'll have to decide whether you want to talk about processes that:
- are happening—so essentially about power and therefore best represented with Sankey arrows
- have happened—so essentially about snapshot to snapshot, and so best represented with bars showing the quantities of energy
Because of this essential distinction, each resource is provided in two forms.
What to Prepare
- a data projector or interactive whiteboard and this interactive object
- access to these resources
Power suggestions
- a car travelling along a motorway
- a leaf photosynthesising
- a bicycle freewheeling
Energy suggestions
- a sprung toy which has jumped into the air
- a bicycle which has freewheeled to a halt
- a car which has braked to a stop
What Happens During this Activity
This activity should be conducted as a teacher-led interactive demonstration using a data projector. Discuss the various situations you choose and use the interactive object with pupils, guiding their views as to stores and pathways. Use the controls to implement your decisions for the values of the power, explaining that the thickness of the arrows in the Sankey diagram represents the power in the pathway.
By the end of the demonstration, pupils should be familiar with the key features of Sankey diagrams and be in a position to start sketching their own diagrams.
Up next
An energy ladder
What the Activity is for
The purpose of this activity is to enable pupils to build up some idea of the size of the joule unit of energy.
What to Prepare
- a blank copy of the ladder, A3 or larger
What Happens During this Activity
Place the ladder on the wall, with a few key values on it, then populate it with energies to give a feeling for the size of the joule and the range of energies connected with human activity. You might like to draw attention to the rather special times scale
up the side where each interval represents a factor of 10 in the quantity of energy.
You might direct the pupils to provide the examples, perhaps researched for homework. If you do this the pupils will need help converting values from calories (1 kilocalorie (kcal) is 4.2 kilojoule) or kilowatt-hours (1 kilowatt hour is 3,600,000 joule).