Modern Engineering Thermodynamics

52 CHAPTER 2: Thermodynamic Concepts
4. The ballistic equation, (2.19), is
V projectile⁡ =
m projectile + m pendulum
m projectile⁡
V pendulum =
5. The conservation mass, or mass balance (MB), Eq. (2.21), is
and the mass rate balance (MRB), Eq. (2.22), is
1 + m
pendulum
½2gRð1 − cos yÞŠ 1/2
m projectile
Mass balanceðMBÞ over time δt = ðδmÞ system
= ∑m in −∑m out
Mass rate balanceðMRBÞ =
dm
= ∑ _m in −∑ _m out
dt system
Important technical terms introduced in this chapter are given in Table 2.2.
Table 2.2 Glossary of Technical Terms Introduced in Chapter 2
thermodynamics
thermodynamic system
system boundary
isolated system
closed system
open system
physical phase
pure substance
homogeneous system
simple substance
thermodynamic state
thermodynamic property
thermodynamic equation of state
intensive property
extensive property
mechanical equilibrium
thermal equilibrium
phase equilibrium
chemical equilibrium
thermodynamic equilibrium
nonequilibrium thermodynamics
thermodynamic processes
thermodynamic cycle
standard atmospheric pressure
absolute pressure
gauge pressure
absolute zero temperature
zeroth law of thermodynamics
the continuum hypothesis
microscopic system analysis
statistical thermodynamics
macroscopic system analysis
the balance equation
the conservation concept
The science and technology that deal with the laws that govern the transformation of energy
from one form to another
A volume containing the item chosen for thermodynamic analysis
The surface of a thermodynamic system
Any system in which neither mass nor energy crosses the system boundary
Any system in which mass does not cross the system boundary, but energy may cross the
system boundary
Any system in which both mass and energy may cross the system boundary
A molecular configuration of matter, categorized as either solid, liquid, or vapor (or gas)
A substance containing a uniform chemical composition in all its physical states
A system containing only a single physical phase of a substance
A homogeneous pure substance
The condition of a thermodynamic system as specified by the values of its independent
thermodynamic properties
Any characteristic of a thermodynamic system that depends on the system’s thermodynamic
state and is independent of how that state is achieved
A formula relating the dependent and independent properties of a system
Any property of a homogeneous system that is independent of the system mass
Any property of a homogeneous system that depends on the mass of the system
A situation where all the mechanical forces within a system are balanced so that there is no
acceleration of the system
A situation where there are no variations in temperature throughout the system
A situation where no phase transformations occur within the system
A situation where no chemical reactions occur within the system
A situation where a system does not have the capacity to spontaneously change its state after
it has been isolated
The study of systems that are not in thermodynamic equilibrium
The path of thermodynamic states that a system passes through as it goes from an initial state
to a final state
A situation where the final thermodynamic state of a process is identical with the initial
thermodynamic state of the process
14.696 psia, 29.92 inches of mercury, 101.325 kPa absolute
Gauge pressure plus the local atmospheric pressure
Absolute pressure minus the local atmospheric pressure
−273.15°C or−459.67°F
If system A is in thermal equilibrium with (i.e., is the same temperature as) system C, and
system B is in thermal equilibrium with system C, then system A is in thermal equilibrium with
system B
Large systems made up of many discrete molecules or atoms may be treated as though they
were made up of a continuous material
The analysis of a system at the atomic level.
The study of atomic level (i.e., microscopic) systems
The analysis of a system at the continuum level
An equation that accounts for all the changes in some quantity within a system
If a quantity is neither produced nor destroyed, then it is said to be conserved