Chapter 1: Introduction and Basic Concepts of Thermodynamics

Vocabulary flashcards covering key definitions, principles, unit concepts, system types, thermodynamic properties, temperature scales, and pressure measurement devices from Chapter 1.

Thermodynamics

The science of energy, derived from the Greek words therme (heat) and dynamis (power).

Conservation of Energy Principle

The principle that during an interaction, energy can change from one form to another but the total amount of energy remains constant; energy cannot be created or destroyed.

First Law of Thermodynamics

An expression of the conservation of energy principle that asserts that energy is a thermodynamic property.

Second Law of Thermodynamics

The law asserting that energy has quality as well as quantity, and actual processes occur in the direction of decreasing quality of energy.

Classical Thermodynamics

A macroscopic approach to the study of thermodynamics that does not require knowledge of the behavior of individual particles.

Statistical Thermodynamics

A microscopic approach to thermodynamics based on the average behavior of large groups of individual particles.

Primary Dimensions

Basic dimensions such as mass $m$, length $L$, time $t$, and temperature $T$ that are selected as fundamental.

Secondary Dimensions

Dimensions expressed in terms of primary dimensions, such as velocity $V$, energy $E$, and volume $V$.

Unity Conversion Ratios

Unitless ratios formed by nonprimary units that are identically equal to 1 and can be inserted into calculations to convert units.

Dimensional Homogeneity

The requirement that every term in an engineering equation must have the same dimensions.

Closed System (Control Mass)

A system consisting of a fixed amount of mass where no mass can cross its boundary.

Open System (Control Volume)

A properly selected region in space, usually enclosing a device that involves mass flow, where both mass and energy can cross the boundary.

Intensive Properties

Properties of a system that are independent of the mass of the system, such as temperature $T$, pressure $P$, and density.

Extensive Properties

Properties of a system whose values depend on the size or extent of the system.

Specific Properties

Extensive properties expressed per unit mass.

Continuum Idealization

Modeling matter as continuous, homogeneous, and without holes, disregarding its atomic nature to treat properties as point functions.

Specific Gravity

The ratio of the density of a substance to the density of some standard substance at a specified temperature, usually water at $4\,^\circ\text{C}$.

Specific Weight

The weight of a unit volume of a substance.

State Postulate

The rule stating that the state of a simple compressible system is completely specified by two independent, intensive properties.

Simple Compressible System

A system that involves no electrical, magnetic, gravitational, motion, and surface tension effects.

Quasi-Equilibrium Process

A process that proceeds in such a manner that the system remains infinitesimally close to an equilibrium state at all times.

Isothermal Process

A thermodynamic process during which the temperature $T$ remains constant.

Isobaric Process

A thermodynamic process during which the pressure $P$ remains constant.

Isochoric Process

A thermodynamic process during which the specific volume $v$ remains constant.

Steady-Flow Process

A process during which a fluid flows through a control volume steadily, meaning properties inside the control volume do not change with time.

Zeroth Law of Thermodynamics

The principle stating that if two bodies are in thermal equilibrium with a third body, they are also in thermal equilibrium with each other.

Triple Point of Water

The state at which all three phases of water coexist in equilibrium, assigned the value $273.16\,\text{K}$ on the thermodynamic temperature scale.

Absolute Pressure

The actual pressure at a given position, measured relative to absolute vacuum (absolute zero pressure).

Gage Pressure

The difference between the absolute pressure and the local atmospheric pressure.

Pascal's Law

The principle that pressure applied to a confined fluid increases the pressure throughout the fluid by the same amount.

Standard Atmosphere

The pressure produced by a column of mercury $760\,\text{mm}$ in height at $0\,^\circ\text{C}$ with density $\rho_{\text{Hg}} = 13{,}595\,\text{kg/m}^3$ under standard gravitational acceleration $g = 9.807\,\text{m/s}^2$.

Bourdon Tube

A mechanical pressure gage consisting of a hollow metal tube bent like a hook whose closed end moves an indicator needle as it deflects.

Piezoelectric Transducers

Solid-state pressure transducers that generate an electric potential in a crystalline substance when subjected to mechanical pressure.