Four identical metal containers, PPP, QQQ, RRR, and SSS, are filled with hot water at 90∘C90^\circ \text{C}90∘C.
The table below describes the outer surface and the top cover of each container:
| Container | Outer surface | Top of the container |
|---|---|---|
| PPP | dull black | no lid |
| QQQ | dull black | fitted with a lid |
| RRR | shiny silver | no lid |
| SSS | shiny silver | fitted with a lid |
Which container will cool down the fastest?
62 exam-style questions on CIE IGCSE Physics 2.3.4 Consequences of thermal energy transfer. Each one has a worked solution and a mark scheme showing where the marks go.