Thermodynamics

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Thermodynamics

• Concerns the study of the Equilibrium properties
  (or quasi-static equilibrium) of a system and its
  surroundings.
• Temperature is a variable, and heat and work are
  somehow involved.
• Heat is energy in transit.

The above system is open.
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Thermodynamics

• Concerns the study of the Equilibrium properties
  (or quasi-static equilibrium) of a system and its
  surroundings.
• Temperature is a variable, and heat and work are
  somehow involved.

• Concerns the study of the Equilibrium properties
  (or quasi-static equilibrium) of a system and its
  surroundings.
• Temperature is a variable, and heat and work are
  somehow involved.
• Heat is energy in transit.

Surroundings
System
Heat
Work
The above system is closed.
3
Thermodynamics

• Concerns the study of the Equilibrium properties
  (or quasi-static equilibrium) of a system and its
  surroundings.
• Temperature is a variable, and heat and work are
  somehow involved.

• Concerns the study of the Equilibrium properties
  (or quasi-static equilibrium) of a system and its
  surroundings.
• Temperature is a variable, and heat and work are
  somehow involved.
• Heat is energy in transit.

Surroundings
System
Work
Mass
The above system is undergoing an adiabatic
change.
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Thermodynamics

• Concerns the study of the Equilibrium properties
  (or quasi-static equilibrium) of a system and its
  surroundings.
• Temperature is a variable, and heat and work are
  somehow involved.

• Concerns the study of the Equilibrium properties
  (or quasi-static equilibrium) of a system and its
  surroundings.
• Temperature is a variable, and heat and work are
  somehow involved.
• Heat is energy in transit.

Surroundings
System
The above system is isolated.
5
Thermodynamics

• Concerns the study of the Equilibrium properties
  (or quasi-static equilibrium) of a system and its
  surroundings.
• Temperature is a variable, and heat and work are
  somehow involved.

• Concerns the study of the Equilibrium properties
  (or quasi-static equilibrium) of a system and its
  surroundings.
• Temperature is a variable, and heat and work are
  somehow involved.
• Heat is energy in transit.

Surroundings
System
System Wall
The above system is isolated.
6
Thermodynamics

• Concerns the study of the Equilibrium properties
  (or quasi-static equilibrium) of a system and its
  surroundings.
• Temperature is a variable, and heat and work are
  somehow involved.

• Concerns the study of the Equilibrium properties
  (or quasi-static equilibrium) of a system and its
  surroundings.
• Temperature is a variable, and heat and work are
  somehow involved.
• Heat is energy in transit.

Surroundings
System
Heat
System Wall
The above is an example of a diathermal wall.
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Equations of state

• An equation of state is a mathematical relation
  between state variables, e.g. p, V T.
• This reduces the number of independent variables
  to two.

General form f (p,V,T) 0 Example pV nmRT
0 (ideal gas law)
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Joules apparatus for measuring the mechanical
equivalent of heat
1 cal 4.184 J will raise temperature of water
by 1 ?C (14.5 ?C to 15.5 ?C)
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Specific heats of ideal gases

• Now that we have an expression for the internal
  energy of an ideal gas, we can calculate the
  specific heats

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