University Physics Volume 2

# Key Terms

### Key Terms

process during which no heat is transferred to or from the system
boundary
imagined walls that separate the system and its surroundings
closed system
system that is mechanically and thermally isolated from its environment
cyclic process
process in which the state of the system at the end is same as the state at the beginning
environment
outside of the system being studied
equation of state
describes properties of matter under given physical conditions
equilibrium
thermal balance established between two objects or parts within a system
extensive variable
variable that is proportional to the amount of matter in the system
first law of thermodynamics
the change in internal energy for any transition between two equilibrium states is $ΔEint=Q−WΔEint=Q−W$
intensive variable
variable that is independent of the amount of matter in the system
internal energy
average of the total mechanical energy of all the molecules or entities in the system
isobaric process
process during which the system’s pressure does not change
isochoric process
process during which the system’s volume does not change
isothermal process
process during which the system’s temperature remains constant
molar heat capacity at constant pressure
quantifies the ratio of the amount of heat added removed to the temperature while measuring at constant pressure
molar heat capacity at constant volume
quantifies the ratio of the amount of heat added removed to the temperature while measuring at constant volume
open system
system that can exchange energy and/or matter with its surroundings
quasi-static process
evolution of a system that goes so slowly that the system involved is always in thermodynamic equilibrium
reversible process
process that can be reverted to restore both the system and its environment back to their original states together
surroundings
environment that interacts with an open system
thermodynamic process
manner in which a state of a system can change from initial state to final state
thermodynamic system
object and focus of thermodynamic study