Thermal physics Flashcards
Evaporation
the process by which a liquid becomes a gas at temperature below its boiling point
Internal energy
the sum of the random distribution of kinetic and potential energies of the atoms or molecules in a system
First law of thermodynamics
∆U = q + W
The increase in internal energy of a body is equal to the thermal energy transferred to it by heating plus the mechanical work done on it
Work done when the volume of a gas changes at constant pressure
W = p∆V
Isothermal change
a change of a system in which the temperature remains constant
Key idea behind thermal energy transfer
thermal energy is transferred from a region of higher temperature to a region of lower temperature
Thermal energy
energy transferred from one object to another object because of a temperature difference, another term for heat energy
Thermal equilibrium
a condition when 2 or more objects have the same temperature so that there is no net flow of energy between them
Thermodynamic scale
a temperature scale in which temperature is measured in kelvin (K)
Absolute zero
the temperature, 0K, at which a system has minimum internal energy; equivalent to -273.15ºC
To convert temperatures between degrees Celsius and Kelvin
θ (in ºC) = T (in K) – 273.15
T (in K) = θ (in ºC) + 273.15
Key idea behind independence of thermodynamic temperatures
thermodynamic temperatures do not depend on the property of any particular substance
Thermocouple
a device consisting of wires of 2 different metals across which an emf is produced when the 2 junctions of the wires are at different temperatures
Range (of values)
the difference between the maximum and minimum values
Specific heat capacity
the energy required by unit mass per unit temperature change
