A system that is not undergoing any change possesses a unique condition defined by its measurable properties, such as temperature, pressure, and volume. This specific condition is known as the state of the system. A complete set of these properties fully describes the state. If the value of any single property changes, the system shifts to a new, distinct […]
All activities in nature involve some interaction between energy and matter; thus, it is hard to imagine an area that does not relate to thermodynamics in some manner. Therefore, developing a good understanding of basic principles of thermodynamics has long been an essential part of engineering education. Thermodynamics is commonly encountered in many engineering systems
Density is defined as mass per unit volume (Fig. 2–3). That is,Density: (2–1) The reciprocal of density is the specific volume v, which is defined as volumeper unit mass. That is, v ! V/m ! 1/r. For a differential volume elementof mass dm and volume dV, density can be expressed as r ! dm/dV.The density
What Is a Fluid? You will recall from physics that a substance exists in three primary phases: solid, liquid, and gas. (At very high temperatures, it also exists as plasma.) A substance in the liquid or gas phase is referred to as a fluid. Distinction between a solid and a fluid is made on the
