Subjects to be discussed:

1

• Subjects to be discussed
• Defn T Av KE
• KE directly proportional to absolute T, KE---kT
• 0th Law A?C B?C Then A?B
• Heat energy transfer due delta T
• U total internal E sum of all KEPE
• Heat conduction ?Q/?t kA (?T/?x)--- kthermal
  conductivity, (..) thermal gradient
• convection heat flow in a fluid medium
• radiation no medium needed for propagation,
  elctromagnetic radiation, P AT4
• Specific Heat Capacity heat needed to raise T
  of 1 kg of a substance by 1 Cº.
• assume C is indep of T. Is it? (J kg-1 K-1)
• Thermal Equilibrium reached at T1T2
• Specific Latent Heat of Fusion heat required to
  melt a unit mass of A at its (normal) melting
  point
• Q m L
• Phase changes
• Idael Gases no V (point newtonian particles),
  no interaction (zero intermolec forces),
• elastic collisions, vacuum between particles
• ½ mv2 3/2 kT v2 (v12 v22 v32 ...)N or
  RMS speed average speed (but actually

2

• U 3/2 NkT 3/2 nRT 3/2 PV for
  point-monoatomic particles. if polyatomic U is
  bigger
• Mechanical work done by gas w P?V (area under
  PV curve at const n, T)
• work done by the sys (negative sign, internal E
  decreases), work done on the sys positive
• Isobaric const P, isochoric const V,
  isothermal const T, adiabatic ?Q0
• 1st LAW ?U q w U state function-capital
  letters, q and w are notlower case
• SOLVE EXAMPLE FROM PETRUCCI, isothermal
  adiabatic expansion waht happens to T, w, q
• and U ?
• 2nd LAW in a heat engine, absorbed heat can not
  be completely converted into work.
• (no 100 ordered flow of energy)
• or in a spontaneous process ?Sunversegt0
• ?S ?Q/T
• Heat does not flow from cold to hot objects
• Effiicieny of a Heat Engine Eff W/Qh (Qh
  Qc)/ Qh lt 1
• The most efficient engine Carnot Heat engine
  Eff (Th-Tc)/Th