Intro to Thermodynamics Flashcards
System
A quantity of matter or region of space within a boundary
Boundary (control surface)
A real or imaginary surface that separates the system from its surroundings
Closed system
A region of space of fixed mass
Isolated system
A closed system that does not interact in any way with its surroundings
Open system
A region of space where both mass and energy can cross the boundary
Intensive properties
Independent of the size of the system
- e.g. temperature, pressure, density
Extensive properties
Dependent on the size of the system
-e.g. mass, volume, energy
Thermodynamic equilibrium
No further changes to properties of system - all properties remain constant with time
Mechanical equilibrium
No change in pressure at any point of system with time - no movement
Quasi-equilibrium process
A transformation from one equilibrium state to another whereby the system remains sufficiently close to an equilibrium state at all times
Thermodynamic cycle
A sequence of processes that begins and ends at the same state (no net change in state)
Internal energy
The sum of all processes that relate to the molecular structure of the system and the degree of molecular activity
Temperature
The measure of the hotness or coldness of a substance
Zeroth Law of Thermodynamics
If two bodies are in thermal equilibrium with a third system, then they are also in thermal equilibrium with each other
Absolute pressure
The actual pressure at a given position
