College Physics

# 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 the Earth that is due to gases such as carbon dioxide and methane that absorb infrared radiation from the Earth’s surface and reradiate it in all directions, thus sending a fraction of it back toward the surface of the 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
$1kilocalorie=1000calories1kilocalorie=1000calories size 12{1"kilocalorie=1000""calories"} {}$
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 $Q net t = σ e A T 2 4 − T 1 4 Q net t = σ e A T 2 4 − T 1 4 size 12{ { {Q rSub { size 8{"net"} } } over {t} } =σeA left (T rSub { size 8{2} } rSup { size 8{4} } - T rSub { size 8{1} } rSup { size 8{4} } right )} {}$
R factor
the ratio of thickness to the conductivity of a material
heat transfer which occurs when microwaves, infrared radiation, visible light, or other electromagnetic radiation is emitted or absorbed
energy transferred by electromagnetic waves directly as a result of a temperature difference
rate of conductive heat transfer
rate of heat transfer from one material to another
specific heat
the amount of heat necessary to change the temperature of 1.00 kg of a substance by 1.00 ºC
$Q t = σ e A T 4 , Q t = σ e A T 4 , size 12{ { {Q} over {t} } =σeAT rSup { size 8{4} } ,} {}$ 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