Week 2: First Law of Thermodynamics Flashcards
System
An identifiable collection of matter upon which attention is focused.
Composite System
A system which, for practical reasons, is broken down into a number of subsystems.
Closed System
A system which is surrounded by an impermeable barrier, i.e. matter cannot enter or leave the system. Can still interact with the surroundings (either through work or heat).
Isolated System
A system which cannot interact in any way with its surroundings.
Property
A measurable characteristic of a system (volume, pressure, temperature).
Specific Property
A property divided by mass.
Extensive Property
A property whose value for a composite system is equal to the sum of the values for its subsystems.
Intensive Property
A property whose value for a composite system is not equal to the sum of the values for its subsystems.
State
The state of a system at any instance is defined by the values of all its properties at that instance.
Equilibrium/Equilibrium State
A state where all the properties of the system are constant.
Process
Any change from one equilibrium state to another.
Real Process
In moving from one equilibrium state to another, a real process will take the system through any number of non-equilibrium states. This is what occurs in the real world.
Quasi-Equilibrium Process
A process which occurs infinitely slowly, and hence the system moves seamlessly through a series of equilibrium states. This is a theoretical idea.
Adiabatic Process
System undergoes NO heating.
Internal Energy Equation
ΣQ + ΣW = E2 - E1
Cycle
A system is said to have undergone a cycle if it undergoes a series of processes such that it eventually returns to its original state (i.e. all its properties are returned to their original values before it started out on the cycle).
