Physics

1
Physics

• Thermodynamics Review

2
Objective

• By the end of this presentation, you will be a
  master in THERMODYNAMICS and be qualified to join
  Mr. Bell in his quest to reverse the escalation
  of ENTROPY.

3
Relationships between heat work

• First Law of Thermodynamics
• DU Q W
• DU Uf Ui Change in Internal Energy
• Q Energy Transfer by Heat
• Q Heat Energy Added to the System (from the
  environment)
• - Q Heat Energy Removed from the System (to the
  Environment)
• W Energy Transfer by Work
• W Work Done on the Environment (Expansion of
  System)
• - W Work Done by the Environment (Compression
  of System)

4
Thermodynamic Processes

• Isovolumetric
• DV 0 W 0 since W P x DV
• DU Q W DU Q
• Isothermal
• DT 0 DU 0
• DU Q W Q W
• Adiabatic
• Q 0
• DU Q W DU W
• Isolated
• DU Q W 0

5
Heat Engines

• Cyclic Process . DU 0
• Qin Q Qh (explosion of gases)
• Qout - Q Qc (colder exhaust)
• Wnet Wout W
• DU Q W W Qh - Qc

6
Refrigeration

• Cyclic Process . DU 0
• Qin Q Qc (removal of colder air from inside
  the refrigerator)
• Qout - Q Qh (warmer exhaust to environment)
• Wnet Win (compression of gas) - W
• DU Q W W Qh - Qc

Qc
Wnet
Qh
7
Efficiency of heat engines

• Second Law of Thermodynamics
• Qc gt 0
• Efficiency W/Qh (Qh-Qc)/Qh 1 Qc/Qh

8
Entropy