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Glossary

# Glossary

conduction
heat transfer through stationary matter by physical contact
convection
heat transfer by the macroscopic movement of fluid
emissivity
measure of how well an object radiates
greenhouse effect
warming of Earth that is due to gases such as carbon dioxide and methane that absorb infrared radiation from Earth’s surface and reradiate it in all directions, thus sending a fraction of it back toward the surface of Earth
heat
the spontaneous transfer of energy due to a temperature difference
heat of sublimation
the energy required to change a substance from the solid phase to the vapor phase
kilocalorie
$1kilocalorie=1,000calories1kilocalorie=1,000calories size 12{1"kilocalorie=1000""calories"} {}$
latent heat coefficient
a physical constant equal to the amount of heat transferred for every 1 kg of a substance during the change in phase of the substance
mechanical equivalent of heat
the work needed to produce the same effects as heat transfer
net rate of heat transfer by radiation
is $Qnett=σeAT24−T14Qnett=σeAT24−T14 size 12{ { {Q rSub { size 8{"net"} } } over {t} } =σeA left (T rSub { size 8{2} } rSup { size 8{4} } - T rSub { size 8{1} } rSup { size 8{4} } right )} {}$
R factor
the ratio of thickness to the conductivity of a material
$Qt=σeAT4,Qt=σeAT4, size 12{ { {Q} over {t} } =σeAT rSup { size 8{4} } ,} {}$ where $σσ$ is the Stefan-Boltzmann constant, $AA$ is the surface area of the object, $TT size 12{T} {}$ is the absolute temperature, and $ee size 12{e} {}$ is the emissivity