Flashcards in Energy Transfer Deck (16)
All objects do what with infra-red radiation?
Emit it and absorb it.
Increasing and object's temperature increases what?
The amount of infra-red radiation it emits.
Dark, matt surfaces are good...
...absorbers and good emitters of infra-red radiation.
Light, shiny surfaces are poor...
...absorbers and poor emitters of infra-red radiation, but they are good reflectors of infra-red radiation.
Kinetic theory states that...
...particles of solids, liquids and gases have different amounts of energy.
Free electrons allow a metal to be a good what?
Conduction usually occurs in what?
Convection occurs in what?
Fluids (liquids and gases).
The bigger the temperature difference with the surroundings...
...the faster the rate at which energy is transferred to the surroundings as heat.
Factors that effect the rate of heat transfer:
Surface area and volume.
Material from which the object is made.
The nature of the surface with which the object is in contact.
U-value is a measure of what?
The rate at which a material transfers heat (how good of an insulator it is).
The lower the U-value...
...the better the insulator.
Solar panels may contain water. What does the sun's radiation do to this water?
It heats it to either provide hot water for the house or heat the building.
Specific heat capacity means what?
The amount of energy required to heat a kg of an object by 1C.
Specific heat capacity is measured in what unit?
J/kgC (Joules per kilogram degree celsius).