Thermo Final Exam Definitions Flashcards
The branch of physical science that deals with the relations between heat and other forms of energy, and of the relationships between all forms of energy.
Thermodynamics
Whatever we want to study.
System
Everything external to the system.
Surroundings
Distinguishes a system from its surroundings.
Boundary
A system that always contains the same matter. No mass transfer across its boundary can occur.
Closed System
Special type of closed system that does not interact in any way with its surroundings.
Isolated System
A given region of space through which mass flows. Mass may cross the boundary.
Control Volume
Characterizes by statistical means the average behavior of the particles making up a system.
Microscopic Approach
Describes the system behavior in terms of the gross effects of the particles making up the system, specifically effects that can be measured with instruments.
Macroscopic Approach
The condition of a system as described by its properties.
State
A transformation from one state to the other.
Process
Property that depends on the size or extent of a system.
Extensive Property
Property that’s independent of the size or extent of a system.
Intensive Property
Pressure with respect to the zero pressure of a complete vacuum.
Absolute Pressure
When the system pressure is greater than the atmospheric pressure.
Gage Pressure
When the atmospheric pressure is greater than the system pressure.
Vacuum Pressure
Physical property that determines whether two objects are in thermal equilibrium.
Temperature
If object A is in thermal equilibrium with object B, and object B is in thermal equilibrium with object C, then object C is also in thermal equilibrium with object A.
0th Law of Thermodynamics
The rate of energy transfer by work.
Power
A process that undergoes a sequence of equilibrium states during the process.
Quasi-Equilibrium Process
A process involving no heat transfer.
Adiabatic Process
The transfer of energy from more energetic particles of a substance to less energetic adjacent particles due to interactions between them (Fourier’s Law).
Conduction
Energy transfer between a solid surface and an adjacent gas or liquid by the combined effects of conduction and bulk flow within the gas or liquid (Newton’s Law of Cooling).
Convection
Energy transported by electromagnetic waves (Stefan-Boltzman Law).
Thermal Radiation
Energy can be neither created nor destroyed during a process, it can only change forms.
1st Law of Thermodynamics
Sequence of processes that begins and ends at the same state.
Thermodynamic Cycle
The change in the amount of energy contained within a system is equal to the net amount of energy transferred in across the system boundary by heat transfer minus the net amount of energy transferred out across the system boundary by work.
Closed System Energy Balance
Projection of the P - v - T surface onto the pressure - temperature plane.
Phase Diagram