4thweek

• Thermodynamics- is the study of heat ad its transformation into work.
• James Prescott Joule (1818-1889)- who demonstrated that the quantity of work necessary to cause a given change of state is independent from the type of work (electric, mechanical, etc.), the method delivering, or the rate of doing work.
• P= pressure

  F= force

  A= area

  *change d= distance/displacement

  *change v= change in volume

  H= height
• Derivation of equation:

  W= F.*CHANGE*D

  W= (AP) *CHANGE* D

  W= P.(A*CHANGE*H)

  W= P.*CHANGE*V
• The word thermodynamics stems from the Greek words thermos and dynamics which mean movement of heat.
• The science of thermodynamics was developed in the mid-1800s before the atomic and molecular nature of matter was understood.
• Thermodynamic process- or a change of state can be described as any change in the values of the following quantities: pressure, volume, temperature, and quantity of a substance.
• State variables- describe the features of a system that are always the same whenever that system is in a given state.
• State- is a particular situation wherein a system has specified values of pressure, volume, temperature, and quantity of a substance.
• Reversible process= if the process can be reversed, otherwise it is an irreversible process. A cycle is a succession of changes that ends with the return of the system to its initial state.
• Isovolumetric or Isochoric process= the first thermodynamics process is the constant volume process.
• Isothermal process= the second thermodynamics process is the constant temperature process.
• Adiabatic process= the third thermodynamics process is when heat content of the system or certain quantity of matter remains constant. It involves no transfer of heat between the system and its surroundings.
• Adiabatic wall= the wall of a system, which does not allow the flow of heat through.
• Diathermic wall= the wall which allows the flow of heat
• First law of thermodynamics= if this energy conservation is applied to thermal system or systems involving changes in temperature.
• Mathematical form of the first law: *change*Q=*change*U + W
• Q= heat transferred to or from the system.

  U= change in the internal energy.

  W= is the external work done by the system.
• Isobaric process= the last thermodynamic process is the constant-pressure process.