Two identical metal cylinders, one painted matte black and the other painted shiny silver, are filled with equal amounts of cold water at the same initial temperature. Both cylinders are placed outdoors in direct sunlight on a clear day.
Why does the water in the matte black cylinder heat up faster?
The matte black paint is a much better thermal conductor than the shiny silver paint.
The matte black surface is a good absorber of infrared radiation from the Sun.
The shiny silver surface prevents internal convection currents from forming.
The matte black paint lowers the specific heat capacity of water.
301 exam-style questions on CIE IGCSE Physics 2.3 Transfer of thermal energy, covering 2.3.1a Thermal conductors and thermal insulators, 2.3.1b Explaining thermal conduction, 2.3.2 Convection, 2.3.3a Thermal radiation, 2.3.3b Surface colour and texture, 2.3.3c Rate of emission and absorption of radiation, and 2.3.4 Consequences of thermal energy transfer. Each one has a worked solution and a mark scheme showing where the marks go.