Latent heat is the heat released or absorbed by
a body during a change of state without change
of temperature.
Specific latent heat of fusion (lf)
definition
The specific latent heat of fusion (lf) of a substance is the quantity of heat needed to change unit mass of solid to liquid without temperature change.
formula
Q=m*lf
Specific latent heat of vaporization (lv)
definition
The specific latent heat of vaporication (lv) of a substance is the quantity of heat needed to change unit mass of liquid to vapor without temperature change.
formula
Q=m*lv
typical values for water
latent heat of fusion=3.33*10^5 J/kg
latent heat of vaporization=2.26*10^6 J/kg
Energy transfer
Conduction
definition
Heat conducts from one point to another only if there is a temperature difference between the two objects.
Convection
definition
Convection is the process by which heat is transferred by movement of a heated fluid, such as air or water.
Radiation
definition
Radiation heat transfer is the energy that is emitted by matter in the form of photons or electromagnetic waves.
electromagnetic spectrum
Heat
definition
Heat (thermal energy) is energy that
transferred between one body and another or
between a system and its surroundings, as a
result of a difference in temperature.
temperature
definition
a measure of how hot or cold an object is
the average kinetic energy of the molecules of the body
unit
degree Celsius (℃)
℃=(℉-32)/1.8
℃=K-273
degree Fahrenheit (°F)
Kelvin (K)
absolute zero=0K=-273℃
measure of temperature
Thermal capacity(C)
definition
The thermal capacity of a body is the quantity of
heat needed to raise the temperature of the
whole body by 1 ℃/K.
formula
C = Q/△T
unit
J/K
J/℃
Specific heat capacity(c)
definition
The specific heat capacity of any substance
is defined as the quantity of heat
required to change the temperature by 1K in a unit mass.
