Pearson Edexcel IGCSE Physics · Year 10–11
Specification points 4.1–4.17. Energy stores and pathways, conservation, efficiency and Sankey diagrams, thermal transfer, work, $mgh$, $\tfrac{1}{2}mv^2$ and power. Physics-only points 4.18P–4.19P (generating electricity) are not taught here.
From your teacher
Every joule that leaves one store must arrive in another. I will keep asking you two questions: which store is emptying and which pathway carries the energy. For calculations: convert first, write the equation, substitute, unit, sense-check. Use $g=10\,\text{N/kg}$ unless the paper gives another value. Efficiency is useful energy divided by the energy supplied, times $100\%$.
State
Name a store, a pathway, or write an equation. One precise sentence.
Calculate
List quantities, convert, equation, substitute, unit. Show the working.
Explain
Cause then effect. “Hot air expands, becomes less dense, rises…” is three marks. “Convection happens” is none.
Lesson A · 4.1–4.5
Units, eight stores, four pathways, conservation, efficiency, Sankey diagrams.
Lesson B · 4.6–4.10
Conduction, convection, radiation, core practical 4.9, insulation and the vacuum flask.
Lesson C · 4.11–4.17
$W=Fd$, $mgh$, $\tfrac{1}{2}mv^2$, conservation with friction, $P=W/t$.
Eight fully marked problems — Sankey, work, $mgh$, $KE$, friction, power, insulation explain.
Double Award covers 4.1–4.17 only. Physics-only 4.18P–4.19P (generating electricity from wind, water, geothermal, solar, fossil fuels and nuclear; advantages and disadvantages of large-scale production) are excluded from this site.
| Point | You must be able to | Lesson |
|---|---|---|
| 4.1 | Use kg, J, m, m/s, m/s², N, s, W and convert (kJ → J, kW → W, g → kg) | A |
| 4.2 | Describe transfers involving the eight stores and name the pathway | A |
| 4.3 | Use conservation of energy — energy is not created or destroyed | A |
| 4.4 | Efficiency = useful energy / total energy supplied $\times 100\%$ | A |
| 4.5 | Read and sketch Sankey diagrams (arrow width $\propto$ energy) | A |
| 4.6 | Describe conduction, convection and radiation | B |
| 4.7 | Explain convection in everyday situations (heater, breeze, fridge, pan) | B |
| 4.8 | Link emission and absorption of infrared to surface colour and temperature | B |
| 4.9 | Core practical: investigate conduction, convection and radiation | B |
| 4.10 | Reduce unwanted transfer — insulation, double glazing, vacuum flask | B |
| 4.11–4.12 | $W=F\times d$ along the force; work done = energy transferred | C |
| 4.13–4.14 | $\Delta GPE=mgh$ and $KE=\tfrac{1}{2}mv^2$ | C |
| 4.15 | Link $mgh$, $KE$ and work against friction | C |
| 4.16–4.17 | Power is the rate of doing work or transferring energy; $P=W/t=E/t$ | C |
| 4.18P–4.19P | Generating electricity — Physics-only. Not taught or examined on this Double Award site. | — |