Heat

Heat

 

Heat


 

Temperature = A measure of the hotness or coldness of a body. Unit = Kelvin (k)

Thermometric property = A physical quantity that changes measurably with temperature. Eg = resistance

Degrees Celsius + 273.15 = Degrees Kelvin.

Types of thermometer = Mercury, alcohol, digital.

Heat capacity = Energy needed to increase temperature of an object by one degree Kelvin. Unit = j/k

Specific heat capacity = Energy needed to heat 1kg of a substance by 1 degree Kelvin. Unit = j/kg/k

Latent heat = heat energy needed to change the state of a substance but not its temperature.

Specific latent heat = Heat energy needed to change state of 1kg of a substance without a temperature change.

Specific latent heat of fusion = Heat energy needed to change 1kg of a substance from a solid to a liquid.

Specific latent heat of vaporization = Heat energy needed to change 1kg of a substance from a liquid to a gas.

Conduction = Transfer of heat in solids by vibrating molecules.

Convection = Transfer of heat in fluids or gas by circulating currents.

Radiation = The transfer of heat from one place to another by electromagnetic means.

U value = the heat energy conducted per second through 1 m2 of a structure when a temperature difference of one degree Celsius is maintained between the ends. Units = W/m2/k.

Solar Constant = The average energy from the sun falling on one meter squared of the earths atmosphere.

Formulae for heat page 58.