How can you tell they’ve got it: Efficiency, Sankey diagrams, and work done?

If they’ve got it, you’ll see things like: Calculates efficiency as a percentage from given input and useful output energy values; Draws a Sankey diagram to represent energy transfers in a device, with arrow widths proportional to energy amounts; Uses W = Fd to calculate work done when a force moves through a distance; Identifies which energy transformations in a Sankey diagram are useful and which are wasted. Or just try it together: If your child heard that a light bulb is 10% efficient and uses 60 J of energy, could they work out how much of that energy actually becomes light — and where the rest goes?

Science Energy Ages 12–13

Efficiency, Sankey diagrams, and work done

Your child can work out how much energy does a useful job. If a bulb is one-tenth efficient, only that share becomes light. The rest turns to heat.

In curriculum terms

Calculate energy efficiency as the ratio of useful output energy to total input energy, construct and interpret Sankey diagrams, and calculate work done using work = force × distance

Ages are typical, not deadlines — follow your child’s pace. How to help at home →

How to tell they’ve got it

Tick these off as you see them — no test required.

Calculates efficiency as a percentage from given input and useful output energy values
Draws a Sankey diagram to represent energy transfers in a device, with arrow widths proportional to energy amounts
Uses W = Fd to calculate work done when a force moves through a distance
Identifies which energy transformations in a Sankey diagram are useful and which are wasted

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Try this together

If your child heard that a light bulb is 10% efficient and uses 60 J of energy, could they work out how much of that energy actually becomes light — and where the rest goes?

Where this sits on the map

Stuck here? Check the skills it builds on first. Confident? Here’s what it unlocks.

Builds on

Energy can't be created or destroyedages 11–12Efficiency calculations quantify how much energy is conserved vs dissipated — conservation and dissipation must be understood first

Calculating Percentagesages 10–11Calculating energy efficiency as a percentage requires percentage calculation skills from Math

Resultant Forcesages 11–12Work done = force × distance links energy to mechanics — understanding forces as vectors provides the context

Efficiency, Sankey diagrams, and work donethis skill · ages 12–13

Unlocks

Heating experiments and Q = mcΔTages 12–13The heating experiment applies the Q = mcΔT equation and efficiency concepts — those calculations must be understood before doing the practical

solid = must come firstdashed = helps

Curriculum alignment

Where this fits in the official school curriculum — our best automated guess, not yet checked by a person.

This skill sits beyond Year 6 in the Australian Curriculum, so no F–6 code is matched. It also sits beyond the NSW K–6 syllabuses. It also sits beyond Level 6 in the Victorian Curriculum.

Nearby on the map

Conduction, convection, and radiationages 12–13 Heating experiments and Q = mcΔTages 12–13 Ohm's Law: voltage, current, resistanceages 12–13 Power: watts and energy per secondages 12–13

All Energy skills →