Systems L.2+3 Wang

Systems L.2+3 Wang

1. type of systems

   • A) Closed
     • no mass croses the boundary but it does through heat (heat to expand volume)
     • Real boundaries, dashed lines. Both movind and fixed boundaries
   • B) Open
     • mass can cross the bound, leave/enter system
     • volume inside an open syst = Control Volume
   • C) Isolated system
     • does not allow any form of energy transformation through its boundary

2. Properties

   • 1. Extensive
     • depend on the size of the system: mass, volume, total energy
   • 2. Intensive
     • Values do not depend on the size of the system: pressure, tmp, density
   • The classification of a property is made without considering any interaction with the surroundings of a system (explanation T and P -volume depended)
   • specific properties
     • divided by mass
       • considered to be intensive properties

3. STATE of a system

   • give a completly description of the conditions of the system (described by calculating the system properties)
   • if one property change>> new state
   • how does it change? >> generally adding or taking energy out of the system will change its state
   • state changing in a real system: continuous change of state bc of the continuous change of properties (P,V,T)

4. Definitions

   • Process: change from one equilibrium state to another
   • Path of the process: series of states connected by the line in a graphical representation
   • Cycle: when a thermodynamical system starts from a state and returns to its initial state
     • process of this system: ciclic process