CP3c Keeping Warm Flashcards
Energy can be transferred by heating in different ways:
Conduction
Convection
Radiation
In conduction…
vibrations are passed on between particle in a solid. This is heat transfer through solids
Material - Good thermal conductor
Metal
Material - Poor thermal conductor (good thermal insulator)
Wood
In covection
part of a fluid that is warmer than the rest rises and sets up a convection current. This is a heat transfer through liquids and gases
Radiation…
Is heat transfer through everything and is the only way energy can be transferred through a vacuum because it is a wave of energy
Thermal conductivity
A measure of how easily energy can pass through a material by heating. Low thermal conductivity = good insulating material
Fluid
A liquid or gas
Insulation
The method of reducing energy transfer
Materials that contain air are good insulator because…
air has a very low thermal conductivity
When air is trapped it cannot form…
convection currents
The rate of energy transfer is reduced by…
increasing thickness, decreasing thermal conductivity and decreasing temperature difference
Cavity walls have an air gap between them which…
helps insulate the house
Infrared radiation is absorbed and emitted easily by…
dark, dull surfaces
Infrared radiation is absorbed and emitted poorly by…
light, shiny surfaces
