Chapter One Flashcards
What is a system?
Whatever we want to study
What are surroundings?
Everything that is external to the system
What is a system boundary?
It distinguishes the system from its surroundings
What is a closed system?
It is defined when a particular quantity of matter is under study.
It always contains the same matter.
What is a control mass?
The same thing as a closed system.
What is an isolated system?
It is a special type of closed system that does not interact in any way with its surroundings.
What is a control volume?
It is a region within a prescribed boundary.
Mass crosses the boundary.
What is an open system?
The same thing as a control volume.
What is a property?
It is a macroscopic characteristic of a system to which a numerical value can be assigned at a given time without knowledge of the previous behavior of the system.
Ex: Mass, volume, energy, pressure, and temperature
What is a state?
It is a condition of a system as described by its properties.
It can often be specified by providing the values of a subset of properties.
All others can be determined by these few.
What is a process?
It is a transformation from one state to another.
What is a steady state?
It is when none of the properties of a system change with time.
What is an extensive property?
It is when the value for an overall system is the sum of its values for the parts into which the system is divided.
Properties that are additive.
Ex: Mass, volume, energy, etc
What is an intensive property?
It is when values are independent of the size or extent of a system and may vary from place to place within the system at any moment.
Properties that are not additive.
Ex: Density
What is equilibrium?
Balance in a system.
What are the four kinds of equilibrium needed to have complete equilibrium?
Mechanical, thermal, phase, and chemical.
What is an equilibrium state?
It is a state of balance.
What is density (ρ) ?
It is mass per unit volume.
It is an intensive property that can vary from point to point.
What is specific volume (ν) ?
It is the volume per unit mass.
It is the reciprocal of the density!
It is an intensive property that can vary from point to point.
What is pressure (p) ?
It is the normal force exerted on a unit area.
It is an intensive property that can vary from point to point.
What is absolute pressure (p) ?
It is the pressure with respect to zero pressure of a complete vacuum.
It must be used in thermodynamic relations.
It is assumed to be the case unless otherwise stated.
What is temperature (T) ?
It is the measurement of the “hotness” or “coldness” of an object.
It is the property used to determine thermal equilibrium.
What is the zeroth law of thermodynamics?
It is if two objects are in thermal equilibrium with a third object, then they are in thermal equilibrium with one another.
What is engineering design?
It is a decision-making process in which principles drawn from engineering and other fields are applied, usually iteratively, to devise a system, system component, or process.
It must work within various constraints.
What is engineering analysis?
It is the consideration of the design, its validity, inputs/outputs, etc.
