The table shows some properties of two materials used as thermal insulation in buildings.
| Material | Raw source | Thermal performance (R-value per inch) | Fire safety properties |
|---|---|---|---|
| Rockwool | Volcanic rock (basalt) | R-3.5 | Non-combustible (withstands up to 1000 °C) |
| Polyurethane foam | Crude oil (petroleum) | R-6.2 | Highly flammable, releases toxic gases when burned |
The higher the R-value, the better the thermal insulating properties of the material per unit thickness.
Assess which of these materials is more suitable to use for insulating a residential home.
Your answer should compare the thermal performance, sustainability of raw materials, and fire safety of both rockwool and polyurethane foam.
82 exam-style questions on Edexcel GCSE Physics 3.1 Energy stores and calculations. Each one has a worked solution and a mark scheme showing where the marks go.