Chapter17 - TE 7 P W 2C P5B 3A5 QP D W BE f 4 PC 5 BC T B 7 R TE 3C Q R 3 I7 B A 2 QP D5a 324 P2 9 DC 5 3 4 I B T4B 8 5C 2 C 7 5 2 3 E g f 4 PC 5 6

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Unformatted text preview: TE 7 P W 2C @ P5B 3A5 QP D W BE f 4 PC 5 BC T B 7 R TE 3C Q R 3 I7 B A 2 QP D5a 324 P2 9 @ DC 5 3 4 I B @ T4B 8 5C 2 C 7 5 2 3 E g f 4 PC 5 6 E P S 3 7 E BC 7 5 D 6 T 4e Yd7 P W P5 4 PC 5 BE 3 7 D 5C T4B D @ 35D 8D QP 8 I7 3 4 3 H46D 3A5 T 4 6 P7 B D 5 3 4 BE a F D 5 2 3 ` U P E BC 5 D 3E 3 2 QP 4 PC 5 P @ 8U T 3 5 B SC 5 P @ YD W BE DX 4 P 5 W3V 8U T 3 47 3 S P I RD @ 35D 8D QP D 3C I7 3 4 3   £¢ ¨  ¦ $  ¤ ¢ ¦ © ¨ '$   ¢ ¦ ¨   %  # ¨ ¦ ©   ¢ ¦  ¦ ¤ ¦¨ ¦§  ¦¢ & ¨ ¢ ¦   ¢ £ ¤   £ ¤¢ ¦© ¨ ¢ £¡  ¢ ¦  ¦ $  ¤ ¢ ¦ © ¨   £ ¨  ¤ ¢ £ ¡    ¢ ¨ !¢ ¦ £  © ¨   ¦¢ ¨  ¢ ¦  ¦   © ¨ £ ¨   ¤ £¢ ¡  #   ©  ¡£ © #  ¢ " ¤ £ ¢ ¡  $  ¦  ¨ ¦ ©  ¤  ¦ ¤¢ ¦ © ¨ § ¦ ¦¢ ¥ • HE B 4 7 3 5 G 3 F E B 2C 4 B A 2 3 @ 9 D 2C 4 B A 2 3 @ 9 87 6 5 4 3 2 10) ( • E B 4 7 3 5 4C 9 D 2C @B4 8TP @ 7 3 A 5 9 D 3C 7 6 5 4 3 2 10 c( T4B 10 b( • 3A5 Y D 2C 4 B A 2 3 @ @ 6 54 B 6 p T4B 8 5C SC 5 B E 3 7 9 87 6 5 4 3 2 10 i h Thermodynamics Some History ( A I6 PA5 ¡ £  &  © ¢ ¤ ¡ § ! ¥   ¥  £ ¡ ©  © ¤  !  § § ¡ %    © ¤  !  § £  #  £ $¤ ¢ ¨  § ¢ §   " £    ¤ ¥  £   © ¤ ¤ ¥ © ¡   ¡ © ¥ #£  §  ¡   "£     ¢ £ ! ¤ ¢  ¤ ¥  £   © £  ¨ §  ¥£ © © ¥   We know what work is, but… What is heat? R52 B7 5D U B 855 37 a D T 4 6 PD DC A 5 E E B R 5 4C P a DC A 5 5 ' £ ¢ © ¥£  %   ©  §   ¥    ¡  £   © ¨ ¡ § ¦ ¥¤ £ ¢ ¡ • • • • • Work: mechanical energy • Heat: thermal energy… ¡ ¥ But what is energy? “We have no knowledge of what energy is …it is an abstract thing…” (Richard Feynman) Definition 1: a scalar quantity that describes the amount of work that can be performed by a force Definition 2: Energy is a property or characteristic (or trait or aspect?) of matter that makes things happen, or, in the case of stored or potential energy, has the "potential" to make things happen. By "happen", we mean to make things move or change condition. Examples of changes in condition are changes in shape, volume, and chemical composition (results of a chemical reaction). There are also changes in pressure, temperature, and density which we call a "change of state" in thermodynamics. Phase changes, such as changing from solid to liquid, or liquid to vapor, or back the other way, are also good examples of condition changes. Something happened! Good, but what about radiation? ©¥ ©¥ © £ ¡¨ ¤ © ¥  ¦    £ ¥ ¤  # ¢  ¦ ¥  ¡  ©   ¨    ¡ ¡ " ¥ §   © §  "£    ¦ £ ©©¥  ¤ £¡ ¦  ¥£ £ ¡ ¦¤ £ ¡ £   © ©¢  ¡  § ¦ § My My definition of energy Definition 3: a scalar quantity conveniently defined so that it is conserved in all physical processes taking place in a closed system, and that obeys certain symmetry principles. Energy comes in many inter convertible forms: -internal (atomic motion in solids, liquids & gases) -electrical & magnetic -chemical - in molecular bonds (coal power) -kinetic (wind power) -potential – gravitational (hydropower) -radiant (solar power) -nuclear – in proton-neutron bonds (nuclear power) … ENERGY obeys conservation laws!!! What is work? Mechanical work: scalar quantity describing the amount of energy transferred by a force acting through a distance W = F .d Units: [W] = [F].[d] = N.m (Newton.meter) = J = Joule % (! ¨ ¦ ¨ £ ©! ¨  ¡ ¥ ¡¦  ¥ ©£ ¨  £ !  ¤ £ ¨ ©  ¡ ¤ ¡   £ ©¤ %! ¨  £ ¤£   ¡ ¤ ! ¨ ¡¡£ © "¨§£'¤ ¥ ¤  ¥  ¡ ¤ ¨  ¥ § ¨¡ ¦ ¦ ¨ B ! ¨¡¡£ ©  £ ¦ ¡¦ ¨ ¤ ¨! ' ¤  §  ¢ % (! ¨ ¦ ¨ £ ©! ¨ ¡  ¨  £ § % (! ¨ ¦ ¨ ¥ ©! ¥ £ ¤ ¨ ¡£ ¨! § ¤ ¨  § ¨ ¥ © ¦£ ¤ © ¥¡£ ¥ ¦ ¥ ¡ ¥ © ¨ &   ¡! ¥ ¦£ 7§£ ( ¦ ¡ £!   !¥ !¨¡¥ §£¨ ¥¡ ¦ ( ¦ ' © ! ¨  ¡ ¨  ¦ ¥ ¡ ¥ © ¦ ¤%£ ¢ £ ¨! £ ¤ ¨  § ¨ ¥ © ¦£ ¤ © ¥¡£ ¨¡ ¦£ A¤ © ¥¡£ ¥ ¤ ( ¦ '  ¥ ! (@ ¤ ¨  § ¨ ¥ © ¦£ ¤ © ¥¡£ ¥ ' ¨£ © ¤ ! ¨ ¡¡£ 9 ¦£ ! ¨ ¡¡ ¥  ¨¡ "¨ ¥ ¥ ' ¨£ © ¤ ! ¨ ¡¡£ ©  £ ¨¡  ¡ ¢  ¨ § £ ' ¨ ! ¦£ ¥¥ ¢ ¨¡ " ¨ § £ ' ¡¤!  ¨¡   ¨! ¨  2 1 ¨!    ¥§ ¡£ ¨ ¢ ¥ ¦¨ ¢ ¨ ¦£' )¨ ¤¡§ ¨$ ¥ § ! ¥ £ § ¤  ¡ ¡§ ¨$ ¥ ¦£ ¦¨¨ ¢¡¨  ¨!! ¨¤ ¦ £! ¡ £ £ ¦ ¨ ¨ ¡  ¨ §¦ £¡¤  ¤ Kinetic-Molecular Theory Internal energy ¨  ¢ ¡§ ¨$ ¥ © %¨¡ ! ¨¡¤£ ¨ & ¦ ¥ ¡ ¥ © ¡¦ £¡¤¦ ¥§ ¦ ¤ ¨  § ¨ ¥ © 8¤ © ¥¡£ ¡£  ¡  ¨¡£¡¤ %! ¥¨¡ ¢¨¦ ¤  &  %! ¥ ¨  ¡ ! £  § ¨ ¥ ©  § ¡ ¨ ¦  7 %!  ¡ ¦ ¨ § 6543 ¨¡ ¦ ¨¦ ¥¦££ ¤£ ¢ %! ¥¨¡ §  ! ¥ £ § ¨ &  ( ¦ ¥ £  £ ¡¥ ¦¨¨ ¨ £   ¥¤ ¨¡ ¦ ¥¥ ¢ ¨¡ ¦ ¦¨¨ £ ¡  1 © ¥!  ¨ © ¥§ §  ! ¥ £ § ¦ ¥ ¡¨¤ ¤ ¡ ¨§¦ ¥ ¥¥ ¢ ¥ ¨ § ¨ '  ¥§ £ © ¥!  ¨¡£¦ £ ©¨ " ¨ ' ©£)¨ ! ¥ " ¦  £ ' ) ¨ ¡¥¦   ¥ § %! ¥ ¨  ¡ ¤  ¡ ¡ 0  ¨¡£¨ % ¢  ¨ ¦ £ ' ) ¨ "¡ ( ¥¡ %¨¡ " ¤  &  ¡ ¥ ¡ ¦ ¢ ¥  ¥¡ £ ' ¡£¨ ¥&   ¨ % ¥! ¡ ¤ ¨  ! ¥¦  ¨ ¡£ ¨! § ! ¨  ¡ ¨ ¦ ¡  ¤¡§ ¨$ ¥ ¨   ¥ § ¡ ¡£¡  ¨  ¨ ¨  ¤£ ¢ ¡ ¦£ # " §  ! ¥ £ §  ¨ ©£¦ ¨   ¤  ¦ ¦£ ¤£ ¢ ¡£¨ ¡£¡  ¨ ¨  ¦ ¥ © © ¥§ ¨§¦ ¥ ¤£ ¢ ¡ % $ ¨  " 0 " $ ¨  " ©  "  ¨   ¨  ¨ #    ! 6 ¨  " 0 " $    #   $  A ¨  P % I   & ¨ (      "      I I  ! $ ¨ ¨ ! ¨ '  &   ¨  # 6    ' " ©  $  A  ¨ I "     #  %  ¨   ¨   $ $  ¨ ( &  ! ¨ #    $ ¨  & ¨ " ©  ¨   0 ¨ #  A " $ $ # § B  ¨  ¨     ¨   ¨ " © $  # &  ¨   (    "  ¨  " © ¨ '  #    " & $ ¨ ¨ !    ' " © 0 " $ H H H G A " ©   0 $ F E $ #  "  $  "  "    $ D C   ¨  ¨    "    ¨ #  " $ 6 " "  ¨ #    $ ¨  & ¨ " © ¨  " © $ ¨ ©   A " $    $  " #  ¨   ¨  ¨ #  6 " "  ¨ #  A "   #    #   ¨   ¨   # &  ©   ¨  ¨ &  ¨   ( ¨    ¨ '  ¨ #  #   " #   ¨ ' ¨ 6 ¨ $   & ¨ !      &   ¨   0  " "  ¨ #    ! 6 ¨      ¨  © ¨   ¨ #  #    %9 17 87  "  6  ¨ $  $ 3 5 1 4 3 2 1   " 0 ¨ #  ¨  " ) %   ¨  ¨ &  ¨   (    & ¨ " © ¨    ¨ '  ¨ #  "     "   "  "     & ¨  $ ¨      ¨  © ¨ § %    #  ¨ ©  $ ¨ #   "    !  ¨   ¨  ¨    ¨  ¨     ¨       ¨      ¨  © ¨ § $  ¨   0  " # ¨ # § %  ¨   0  " & A "    A  " "     © ©  0 $      ¨   0  " # A "  ¨ ( &  !   ¨  $  " @ http://mutuslab.cs.uwindsor.ca/schurko/animations/particlesinmetals/eqilibrium-v1.htm ¦¢ & ¨ ¢ ¦    ¨ A ¤  ¡ ¤! ¥   ( ¨ ¦  £ ¡ ¦ ¨ ¡ ¥ ' ¥ " ¤ ¨¡ Temperature vs. Internal Energy ¨©¨ # ¨ ¦   § ¤¦ ¨ 7  ¦£ % (! ¨ ¦ ¨  ¡ !¥ http://www.absorblearning.com/media/item.action?quick=ad   ¨  ¨ &  ¨   ( ¨  " © $  # ¨ ¨ !  ¨  ¨ ¦  ¦$ & # ¦$ £ ¤ ¦  ¢ ¦ ¢£ ¦#  ¨ ¥ & ¦©¨  & ¡£ ¦§  ¤  ¤ £¨ ¦©¨  ¢ ¦  ¦  ¤  £ ¨ $   £ ¨¢ £  £ ¢  ¤¦¨ £¤  ¨ ¦¢  ¢ ¦ ©  © £ ¦ ¦¢ & ¨ ¢ ¦  ¢£     ¦©¨ ¤    ¨ ¢ ¢ ¦¨ ¡ ¥ ¤ ¦©¨ ¤  ¦$ & # ¦$ £ ¢ ¦¨¨ £ © ¦©   © ¨ ¦ ¤ £  £ ¨!  ¡§! ¡¤ ¨ § ¡ ¡ £ £ ¦  ¨ 7 § ¥ ¡¥¦ ¨! £ ¤¨¤£( ¦£ ¤   ¢ ¡ @ ¤   ¨  §¡¨! ¡¤  ¨ ¤¤ ¨! ' © ¥§ ¨! £ ¤ ( ¦ ! ' ¤ ¨¡ " ¨ ¡ £!   ¤ ¨  § ¨ ¥ © ¨¡  ¤ ( ¦! ' ¤ % ¤ ¡ ¥¡ ¦ ¥ ¨! £ ¤ ¨   § ¨ ¥ © ¤ ¡ ¥  £  §  ¢ ¦  ¥¤ £ ¨ ¦ ( £ © " % (! ¨ ¦ ¨ ¨¡  ¦ £ ¡ ¤! ¨  ¦  ¥&  ¤ ¨  § ¡ ! £ ' ¨¡ ¥ ¦ ¥ ¡ ¥ © ¨¡ ¥¡ ¨ " ¨ ¤!  ¥ § § ¡ ¨ ¦  7 ¨ & ' ¡ ¨7 £ © ¡£  ¡ ¤ ¨ § ¡! £ ' ¨  ¡  £ ¥ ¤ ¦ ¥ ¡ ¥ © © ¥  ¦ £! ¢  ¨ ¡ £ § ¥ ¤ ¤ £ ¤ ¨ (! ¨ ¦ ¨  £ ¡ ¦ ¨ ¡ ¥ ' ¦£ § ¡ ¨ ¦  7 ¨¡ ¥¡ ¨ ¤ ¨ §¦ £¡¤  ¤ ¡§ ¨$ ¥ ¦£ % (! ¨ ¦ ¨ ¨¡ ¤ A % (! ¨ ¦ ¨ £ ©! ¨  ¡  ¨  £ § ¥ ¤ £ @ % (! ¨ ¦ ¨  £ ¦ ! ¨ ¡ ¦ Internal Energy (contd.) http://mutuslab.cs.uwindsor.ca/schurko/animations/particlesinmetals/eqilibrium-v1.htm § ©     ¡£ #     © £ ¡ £   © ¡  ¥ ¡ ©   ¡ !   ¡   ¡ £ ¨   £ £  ¨ §  ¥ £ © "    !  ¡ © ¡     "£       ¡ ! ¥   §    " £    £ ¥¤ ¢  ¤ ¡  ' ) %( '& %   © ¡ © ¤ ¥  ¡ ©£ ¡ % ¡ £ %   $    # " §   ¡ ! ¥   §   § ¤   ©£ ¥ % ¨ ¡ §  " £     ©    ¤ ¥ ©   © ¡ %   © ¡ ©  ¢   "£     £ ¥            ¡¦  ¥ ©£ ¨ ©£¤ ¨¡ %  ¨ ¤ £ ¨! § ¦ ¤ ¤ ! ¨¡£ ¢ ¨¡ ¨   ¢ "  ¨¤ £ ¨! § ¨  ¤ % (! ¨ ¦ ¨  £ ¦! ¨ ¡ ¦ ¤  ¥¡£¡ ¥' ¨¡ ©!  ¨¡£ ¢  ¥ § ¨¡ ¥¡ ¥¡£¡¥' ¡¥ ¨¡ © ¥!  A! ¨¤ ¦ £! ¡ % (! ¨ ¦ ¨@ ¢ ¥  ¡£ ¨ £ ¤ ¨! ¨  & ¡£ ¨  ¡ ¥£ 7 £ ¡ ¦£§ ¨ ¢ "! ¨ ¡ £ ¢  ¥§ ¥ ¢ ¥ £ ¦  ¨ ' ' ¥!  ¤ ¥¡£¡ ¥' ¡£¡   ¤ ¨  § ¨ ¥ © ¤ ¡ ¥ ¦ ¥ ¡ ¥ © ¨¡ ¥ ¡¦ ¥§§£ ¦ ¥ % (! ¨ ¦ ¨  £ ¦! ¨ ¡ ¦ ¥£¨ ¥¥( ¤¨¤¤¨¤¤ ¥' ¡ ! ¨  ¡£! ©¡£ ¨ ¤¤¨¤¤¥' ¡¥¦ ¤¨ ¥ ¥¡£¡ ¥' ¡¥ £ " %  £ §  ¦  § ¨ &  ¤ ¨  ¥  ¦¨¨ ¢¡¨   ¨!! ¨ ¤ ¦ £! ¡ ¤ ¡ ¦¨ ¢ % (! ¨ ¦ ¨  £ ¦ ! ¨ ¡ ¦ ¤ ¡£¨ ¨ ¤  ©¨¡ ¦¨¨ ¢¡¨ ¡§£ ¡£¡ ¤ ¨ §! ¥ ¥¡ ¨ !¨¡¥¦ £ ¥¡ % ¥ ¨¦ ¥ © ¥!   ¨!! ¨¤ ¦ £! ¡ ¡£  ¡ % (! ¨ ¦ ¨ ¨¡ ¤  §  " §¦ ¥ ¤ ¥ £ ¨  ¨¡ ¥¡ ! £  © ¤ ¤ ¤  &  ¨!  ¡£! ¨ ' ©¨¡ ¦ ¨ § ¦ ¨ ! ¨    £ ¥¡ ¨ ¦ ¥ ¡ £ § ¥ ! ¥ % ¥ ¨¦ ¥ © ¥!   ¨!! ¨  ¤ ¦ £! ¡ ¤ ¡£  ¡ % (! ¨ ¦ ¨ ¨¡ ¤ ¤! ¨  ¨! £¢¡ ©! ¨¡ ¨ • • £ ¢ & ! • 0 Internal Energy vs. Heat Summary of concepts CPS question: Which one is “colder” (has lower temperature?) ICE CUBE a) The iceberg b) The ice cube c) They both have the same temperature ICEBERG CPS question: Which one has more “internal energy” ICE CUBE a) The iceberg b) The ice cube c) They both have the same energy ICEBERG What is Heat? What causes it? § © ¡  ¡   ¤ §  ©   ¡ ¤ ¨  ¦ ¨ ¨  §  ¡   § ¤ © ¦ ¦  ¨ ¨  § ¥  ¥  © ¨ ¦ ¥ ¤     ¥  ¡ §  ¥  ¥  ¢   ¨ ¦ © ¨ ¦ ¥ § ¦ ¦ ¥ ¤ ¤£ ¢ ¡ ¡ The Concept of Temperature •Without realizing its significance, Galileo (ca 1630) developed a crude thermometer •Fahrenheit (1715); measured temperature by expansion of a fluid (mercury) •Celsius (1742) defined 0oC as the melting point of ice; 100oC as the boiling point of water; with a scale in between linear with expansion of fluid •Lavoisier (1780) realized that matter is composed of discrete atoms and molecules •Dalton (1808), temperature interpreted as a measure of particle speed (gas) or vibration (solid) •Kelvin (ca 1885) introduced the notion of the absolute zero temperature, where all atomic motion stops ¨!  ¡ £! ¨ ' ©¨¡ ¨ (! £ ! ¥§ ¨! ¦£§  £ ©¤ £ "¨¤¦ ¨ ¥¤ ¤  ¡ 9 ¨¤£§¨ #¦ ¥ ¦ ¨¤ ¥ § ¤£ ¢ %!  §! ¨  ¨ ¤ ! ¤ ¨!  ¡£! ¨ ' ¤£ ¨ ©  ¥ ¦ ¨ ¤ £ ¨! § ¦ ¨¡ ¨ ¨ ¤  ¢   ¢ ¥ ! ¨ ¦ £ ¡ ¦ ¥ §  £  ¡¦ £¡¤¦ ¥§ ¡' ¨7 ¤ ¨ ©  ¥  ¨ ¤ ! ¨!  ¤ ¤ ¨! ' ¢ ¥  ¤  ¢ ¤£ ( ¥ ! ¨  ¦  % § ¨¥ ¤ ¡£ ¨  ¤¡§ £! ¡¦ ¥§ ¦£ ¨£  ¤¦£' )¨  §  ¢ ¨ ' © £¤   ¢ £ ¥ ¨ (£¡¦ £  £ ¨7 £¡ ¢ ¥ ¨   ¨ ¦ ¥ ¡ ¦ ¨ ¤ ¨ §  ¨  ¥ ¢¡ ¨¡ ¡  "¨!  ¡£! ¨ ' ¨!  ¤ £ ¨ © ¥¡ ¤%£ ¢ %¦ £ © ¨! £ CPS question The illustration shows a thermometer that uses a column of liquid (usually mercury or ethanol) to measure air temperature. In thermal equilibrium, this thermometer measures the temperature of ©¤  © ¨! ¤ ¡£ ¨ ! ¥ ¤£( © © ¨¡ ¨! ¨  & – – – E. all of A., B., and C. D. both A. and B. C. the air outside the thermometer. B. the glass that encloses the liquid. A. the column of liquid.  ¤ ¨ (¦ £! ¨ ©  ¥ % ! £ ¨ © ¨¡   ¢ Measuring temperature (cont) Temperature scales Values on the temperatures scales (Fahrenheit, Centigrade/Celsius, and Kelvin) may be readily interconverted. Physics professors will want values to eventually be in Kelvins because that’s the form in SI units. Temperature conversions 210 You only need to remember: 1K = 1 ° C $# $# ° 6 $ ¨      ¨  © ¨  &  A & ¨  $   #   ¨ #    ⁄° ⁄ # $ ) $ 5#  " @ 210 ° × ° ×⁄− 43 % ! % # $  )    $ # 43 "! ° ° − 8 ×⁄ ° ¨ ¦ ¤ § ¦ ¥ ¤ £ ¢ °  @    ¡  from Fahrenheit % %      76   )  9 12 4 37 G ¨    ¨  © ¨   "  @       © (  '  & ×⁄ % ©   !  §   ©  ¨ #    "  ¨       "  ¨ # § % $ ¨  " ! " 0  ¨ #   ¨ ¨ 0  ¨ ! $ # § % ¨      ¨  © ¨  ¨ ©  $ ¨ #    ¨   %      "     ¦ ¨    $ ¨ $   A "  ¨ 0$  ¨# § ¨ 0 " 0" £ ¤  ¨    & ¨ 0 ¨ $ "  & 0 " # "   ©   "  $  ¨  ¨ #    ! 6  ¨ # &  ¨  ¨ !  ¨ ' ¨    & "  ¨ I ¨    " $ ! F %   " 6@ 1 ! G% 4 $ $ # § %   ¨  ¨     ¨    "  ¨ I ¨ '  #   " 0 ¨ &    $ !  $     "  # & # 0   6 "  ¨ I ¨    " $ !  ¨      ¨  © ¨  ¨  !  $ $ "   $ ¨   " & ¨ #  $     "  "  ¨ I $     #  " $    ¨ $ $  ¨   & $   ' ¨ ) ¨ # § ° Absolute Zero & the Kelvin Scale http://jersey.uoregon.edu/vlab/Thermodynamics/index.html % ¨ ¨ #   ¨  ¨   ¨ # A " 0 "  A  ¨  "  $ ¨  ¨ # § ¨   ©  ¨ #    ¨   ¨  " A ¨  ¨ #  6     © ¨  ¨ ©  $ ¨ #    ¨   $  & ¨ ¨ ! " ¨     " 0  ¨ # §  89  7 1 3 © 73 7 8     98 % ¨  $  " & ¨ #  "  ¨   $  " # ¨ #  © "  A    0 " A $ ¨ #  6 $  © ¨    ¨  ¨ A A    ¨     ¨  ¨   ©  ¨ #  A " ¨    # & ¦ ¨  ¨  "  $ ¨  ¨ #  $   ¨ © § ¨ #  A ©    !     ¨      ¨  © ¨    #     ¨ ¨ !  ¨ ' ¨ $  #    #  "  A 6 $  "  ¨ I ¨    " $ !    " & 0 " # 0 "  ( $¢ % "  ¨ I ¨    " $ !  A " $   ' ¨ ( Thermal Equilibrium  ¨   '   " A ¨      ¨  © ¨ § % $ ' ¨   $ $ ¨  H G   #  0 "  $ ¨ &    $ !  $  ¨  " " & ¨ '  # $  $    ¨  & ¡ %  "  23 heat  78 ¨ #  ¨ &  $   ! 6  &    " &  ¨  $  & ¨ ¨ ! " A " ¨   ©  ¨ #    ¨ ! "    $ ¨   $ ¨  " ! " 0 § ° °  ©  ¨  ¨    6 ©    !    § ¨ ¥   #    ! $ % 210 ° ©¨ •expansion of a body •producing mechanical work •increasing the temperature of a body •melting a body •vaporizing a liquid Phase transitions •Liquefying a gas  §  ¤ ¦¨   ¢&£ ¥ ¡ $ & ¡ ¦  & ©#¦ © ¨ "  ¤ &¢ § ¡ ¤¦©¨ ¦¦ ¦ ¤   ¡£ ¦¢   ¦  £ ¤ ¦¨  ¦¢ & ¨ ¢ ¦  £¨ ¦¢ & ¨ ¢ ¦  The 0th law of thermodynamics Effects of heat: ¨£ ¢£ ¤ &¢ ¥ $  & £ ¦ $  ¤¢ ¦© ¨ ¨  ¦¢  " ¦©¨ ¢ ¦©¨¦©  ¦ ¨  #     ¢ ¦ ¨ ¦ ¤ £ ¤ ¢ ¦ © ¨ ¨©   © ¢ ¦¨¦ ¤ £ ¤¢ ¦© ¨ ¦§  ¤ £ ¢¦©¨£ ¥$ & £ ¦ $  ¤¢ ¦ © ¨  £ $  ¦¢   "  § ¦©¨  © ¨ ¤ &¢ ¥ $  & £ ¦ $  ¤¢ ¦© ¨ $ $   ¨   ¥ ¡¦ ¥ % ¢ $ $ £ ¢ £ ¨¦ ¨  ¥ £$ ¡ ¨¦© & £  ¦¢ ¦ © ¨  ¡ ! ¦¢ & ¨ ¢ ¦   ¦  £ ¤ ¦¨ £ ¤ &¢ ¥ $  £ ¦ $  ¤¢ ¦© ¨ ¦¢  ¥ £ ¤ ¥ ¦©¨ ¦©¨ ¤ &¢ ¥ $  & £ ¦ $  ¤¢ ¦ © ¨ ¢ ¡ ¦ ¤  ¦©¨ ¦¢   ¦  £ £$ ¡£ ¥ £ £ ¨ ¦©¨ ¦©¨ ¦ © ¨ $ ¨  & ¦¢ & ¨ ¢ ¦  ¡£ £ ¤ ¦¨ ¢ ¦ ¤ £¢ ¡ ¥ ¤ ¦ ¨ ¢ ¦ ©  © ¥ ¦©¨ £$ ¡ $ $  ¨¦ Thermal expansion—linear • A change in length will accompany a change in temperature. The size of the change will depend on the material. • The change in length is proportional to the temperature change and the initial length: ∆L = αL0 ∆T α is the linear expansion coefficient and is material dependent Nice property for building thermometers! (e.g. mercury) CPS question A solid object has a hole in it. Which of these illustrations more correctly shows how the size of the object and the hole change as the temperature increases? A. illustration #1 B. illustration #2 #1 #2 C. The answer depends on the material of which the object is made. D. The answer depends on how much the temperature increases. E. Both C. and D. are correct. http://freedrive.com/file/831762 Measuring Heat   & £¢  $  ¨  ¦ ¨ £  ¦©¨ ¦ ¦ – Quantity of Heat Calorie: amount of heat needed to raise the temperature of 1 gram of water from 14.5 ° to 15.5 ° C C Since heat is another form of energy, there must be a relationship between these units and the familiar mechanical energy units. Experimentally, one finds: 1 cal = 4.186 J The calorie is NOT a fundamental SI unit. The Joule IS the standard unit of energy ¦ ¦  ¢ £ #   ¦   £¢   ¥    ¢ ¦  ¦  ¤¢  ¦ ¢ £ ¨  £ ¤ ¦$     ¦ ¦ ¨ ¢ & # #  ¨¦© ¦¢  £  &$ #  £ #     $  ¨  ¦ ¨ £  ¥  £ ¨  ¦¨¦ ¤ £ ¤¢ ¦ © ¨ £ £ ¨# ¦  £# ¤¢ £¡ £ ¨ ! # ¨ ¦  § ¨# ¦¡  ¦ ¤¢    ¢ & ¨  ¢ ¦  ¦ ¢ ¦¨ ¢ ¦ ¦ £# ¥ ¤ ¢ © ¨ £ £ ©  ¤ ¥  £¨   –  ¤  ¦§ ¦$ & £ Specific heat ∆ ∆ Q = mc∆T – For water: c = 1 cal/(g C )=4190 J/(kg K) SI units http://www.chem.iastate.edu/group/Greenbowe/sections/projectfolder/flashfiles/thermochem/heat_metal.html Definitions: Specific Heat is the amount of heat required to change temperature of one kilogram of a substance by one degree. Heat Capacity of a system is the amount of heat required to change the temperature of the whole system by one degree. It’s an extensive quantity. Heat capacity = Specific Heat x Mass. C=c.m Molar Heat Capacity specific heat in units of “Moles”, a certain number of atoms (Avogadro constant) Avogadro constant ¦  ¨ 0 A"  © ¨ " $ $  ¨ $    "    ¨ # A "   & G !  " $ !     0 ¥ (   © # &  ¨ ! ¢  $  ¨   E @¦G ! ¨    ¨  © ¨  ¤ – –  ¨ '   $ !  " $ !  ¨ &    $ !  $  A "    " ©   ¨ '     ¨   ©      ¨ & A " $  ¨ ' ¨     ¨ # 0 ¨    # &  0 ¨    ¨  © ¨  # &  © 0 " # E¡    #  " ! "     "   "  "      " A $ ¡ ! $ $  ©  A " ¨    ¨  © ¨  – ¨ #  ¨ $   "   ¨    £ ¢   ¨ # &  A & ¨  $ F E $   " 0  ¨ #  "  C §   ¨   ¨  ¨     ¨   © $ ¨   ¨ # A "    " ©  ¨ # § % ¨# A"   " ©   Specific heat values Small !!! Small !!! ? (Dulong and Petit) LARGE !!! Phases of matter Water, Steam, Ice   ¦ £ ' ¤¦ ¦ ¨ $ ¡ & §¦ ¨ ¤    ¤ ¤"©  % ¨ ¦ $ ¡ ¦  ¨ ¤ ¤  !   £ # ¡ § "!  ©  ¦   !  ¥ £ ¤  © £¨ ¥ £  © ¡ ¤ ¦   ¦ £  ¥ ©   ©     ©¨ §¦ ¥ ¤ £ ¢ ¡ ! ¦  ©  ¨  ¦ ¢ ¦ ¡ ¡   ¦¢ & ¨# &¢ ¨ ¦$ & # ¦$ £ ¤ ¢ $ £ £¨  £" ¤¢ £¡ •Liquid •Solid (ice) •Gas (steam) Water exists in a few phases Water Gas  ¤ "©   ¥£© ©  #¡ ¦  ¨ ¤ ¤  !   £  ©  ¡ § "!  ©  ¦   !  !  ¥ ! ¥¤ §¦ !   ! £ ¥ £ ¤  © £¨ ¥ £  © ¡ £ ¥ ©¨  ©  £  ¤ ¦   ¦ £ ¢ ¡ § "!  ©  ¦   !  ¤ ©¨    ©  ¤  £ £¦ £ ¥ ©¨ Liquid Liquid Solid & §¦ ¨ ¤    ¤ ¤ "©  % ¨ ¦ $ ¡ ¦  ¨ ¤ ¤  !   £  ©  ¡ ¥ £ ¤  © £¨ ¥ £  © ¡ ©£ §¦  ¤ £ £ ¦ ¤  ¦    ¦ £ ¢ ¡ ¤    ¥ ¤ ¢ !  ¥  £ ¨  ¡¨ ¦ ¡ ¦  ¡ ¥ ¤¤ © ¥  ¥ ¤¨  ¤  ¤  ¨ A   $   " A ¨ &C Water most dense at 4 C B #    ¨  " ¨ !  $ $ "  Generally: Generally: •Liquids denser than gas •Solids denser than liquids Phase equilibrium Not water! ° # ¥ ¤ !  ¥  £ ¨  ¡¨¦ ¢   ¡ ¤  ¥ !  ! ¥©   '  ¦ ¤ ¦   ¦ £ ¢ ¡ !  ¥ !     ¥  © £   ¦  ¨ ¥¦  ¢ ¡ ° # ¥¥§ Phase transitions Phase •Transformation from one phase to another •Absorbs/releases latent heat (energy in bonds) •Represents a change in order Whenever a substance undergoes a phase transition, energy is transferred into or out of the substance WITHOUT causing a change in temperature. Example: Phase transition - melting heat sublimation freezing melting condensation deposition Latent heat http://www.absorblearning.com/media/item.action?quick=zw Video demo: http://www.youtube.com/watch?gl=GB&hl=en-GB&v=1PcnCWZP7l0 ¨¢© ¨¢© evaporation "  "   I  "   ' A "   ¨ # E    ©  ¢©¨§ ¢©¨ § )     ( #  &   $  ' &  % $ #  "    ! ¦ ¥ ¤ £ ¦ ¥ ¤ £ ¡  D  " $  A A "   ¨ # 0        ¢ ¡ ¢ ¡ Phase transitions: Example Energy required to convert 1 g of ice, initially at -30°C to steam at 120 °C. Specific Heat of: (in J/g K) Water: 4.19; Steam: 2.01; Ice: 2.06 Latent heat of fusion: 334 J/g Latent heat of vaporization: 2260 J/g Phase transitions Phase can be affected by pressure pressure Summary: Phase changes and temperature behavior • A solid will absorb heat according to its heat capacity, becoming a hotter solid. • At the melting point, a solid will absorb its heat of fusion and become a liquid. An equilibrium mixture of a substance in both its liquid and solid phases will have a constant temperature. • A cold liquid will absorb heat according to its heat capacity to become a hotter liquid. • At the boiling point, a liquid will absorb its heat of vaporization and become a gas. An equilibrium mixture of liquid and gas will have a constant temperature. • A cold gas can absorb heat according to its heat capacity and become a hotter gas. CPS Question A pitcher contains 0.50 kg of liquid water and 0.50 kg of ice at 0° You let C. heat flow into the pitcher until there is 0.75 kg of liquid water and 0.25 kg of ice. During this process, A. the temperature of the ice-water mixture increases slightly. B. the temperature of the ice-water mixture decreases slightly. C. the temperature of the ice-water mixture remains the same. D. The answer depends on the rate at which heat flows. ¨   ! ¦  ¨ ¦!  © ¨   ¦$ ¦ ¦£ ¦©¨ ¨# ¦¢  Heats of Fusion and Heats of Vaporization http://www.kangwon.ac.kr/~sericc/sci_lab/physics/conduction/conduction.html ©#& ¤ £ ¥¢   ¤ ¢ ¦$ £ £ # ¢ ¦ $ £ # ¡£  ¦$ & # ¦$ £  ¦¢  http://www.wisc-online.com/ViewObject.aspx?ID=SCE304 ¦   ¦ ¨    ¢ ¥¢ £ ¥  $$ ¨ ¤ &¢ ¥ $  & £ ¦$ ¤¢ ¦ © ¨ ¨ § ¦$$ ¦  ¢ £¡  £ ¨    ¢ ¢    ¦ # ¦  ¦ § $  ¥  ¨# ¦¡ ¡£ ¥ ¦  £ ¨    ¢ ¤ &  ¦ ¤  ¦$ ©  & £¢ © ¨ ¢ ¦ ¡  ¢ ¨ £   £ ¨ # ¦ ¨ ©  $   ¢£ ¨ ¨¦© ¢ ¦ ¨¨  ¤ ¤  £#   £ ¨ # &   £ # # ¨ ¦      ¦$ ¥  ¤  ¥  ¤ ¡£  £ ¨    ¢ ¨# ¦¡  ¤ £ ¢ ¨ # ¦$ ¦ ¦ ¨    ¢  ¦¢ & ¨ ¢ ¦  ¤ ¦¨  & ¥ £ $$  § %  £ ¢¨ § ¨ ¤    ¨  ¦¢ ¢ & #  ¤ ¦!  £¨ £ £$    &$ ¡ ¥ ¦ £ ¤ £¢ ¡  ¦¢¢ ¦ ¡  ¢ ¨  ¢ ¦  © % £ ¢¨ § ¦   £ ¢ ¡ ¦ ¨# ¦¡ ¥ £ ¦©¨   ¤ ¤¢   £  & ¤& ¨ ¦¦ ¨# ¦¡ £¨ ¤¦©¨ ¦& # ¡£  ¨# ¦¡ ¥ ¦ £ ¢ ¦ $ £ # £ ¨  ¥ ¥ £ ¢ ¦ ¨¨ £ © ¦©¨   ¦$ & # ¦$ £  ¨# ¨ £# ¨# ¦¡ ¥ £ ¦©  ¦¢ ¢ ¦ ¡  ¢ ¨  ¢ ¦  © % £ ¢¨ § ¦ ¥ ¤ £ ¢ ¡ Heat Transfer Processes  36 2 76  3 88" 87 1 7 8 46 39 #  39 8 4 37 1  ¨    #§ & #    %    %   '   &     %  %   &   '     (   (   %  &© ¨ ! & #   § § # $ $     §  &   !  "      § ! $  § # ¤     (  %   §  % (   ¦  & ( # "  ( # §  ¤ #   & # &  &  %  ¨  '  &  $   &  ¥ ¤ #   & #   %   § ! $ § # ¤     (  #  &    ¤ ! ¦  #   #§    % " &  § "     ' &  § ' '      % $  % (   ¤ #   & #    %  %   (  $   & # $  $    " &       '   &  $    &  ¥  §   § %   (    § ! $  § # ¤     (  %  ¨  § # # $  # %   %    § ( # §    # ¤ " &          § ¥ $  !     (  %  #   # %   %  ¤ #    ( #§     %    " § # $       (  %    !  $   ¨     (  #   ¥ $ ! ¦  &   ' &     "  ¦  § # # $ &  %  " &       %  #    § §  ¤  %  (   & #  " & ! #        &   # %   %   !     % ¥ $   "  ¤ $ £   ! §  %   $ !      # %   %  #   # %     # %   ' #  #    "  # &© ¨ %  ¤  ¥ $ § ¦   ¤ # $  ¦ #    " $  " ¥ $  "  ¤ % $ £ %  "       ¨  A   "   ©  ¨ # § B  ¨ A $    $ $  © " ) $    $   A ¨  ©  ¦  "     ¢ $  ¨    ¨   " & "    ¨ $  $  ¨    ¨ ©   0 E $ ¨ $      $   §    C        A  " #     "    ( " " & ¨  ©  ¦  "  & ¨ '  " @ $ ¨  & ¨ " © A "  " $   " &  ' ¡ ©   !   & ¨ ¨ ! "  ¨  " & "   ¨ ©   0 © "  A $ 0 " A   ¨   & ¨ ¨ A A " & ¨  ©  ¦  "  &    " @ How does heat travel? Conduction § ¨      £ ¨ #   & #   ¤  ¤ !   ¦§  ! §  ¦ § §  ( ! & #    #  ¦  & #   "     &  %  " &       %  %  (  §  ¤   %  &   ¦ § §  (   % ' ! # &  ' & #§ § # # $ ! ¨ & ( # " § # # $ § §  !  &     ¥ $ ! ¦ ¡ "  ¤ % $ £ &  %  § §  (   § # $ # % $  # %  # § § !  §   # ¦  # ¤   %   $       &  ¦ &   $ ¦ # &    ¨ ¤ ! ! $   ¦ "  " & ! #   !       %   ¤   (  # § # # $ &  $ & #   "  ¥ ¤¨ ¥  "  %  £ #    "  # &   % '§ "      &  ' &   $    "  ¦  $     %   #  '    &   "    ¥    ' #§ # & % $   & #      % '  ¢ ¨  ¦  #  ¦   &  %    # ¤   ¤     ' &  " & ! #   !    &  %    ¤   (    " # ¦  &  % (  ! ¦  & #    "   ¦  #  ¦  § §  ! &   & # $ # §     " #  ¨ "      &       #   !  #  ' & #§ # #     %  %  ' & §    (   #  % ' §  ¡  § §  !  !  ! ¦   % ' § §  ¤       %  ¨ & #     "   $    & '  ¤ #   $  §  ' &    ¤   ¦     %  #   '   &      &    # §  &  $     (  %  ¨ & #  $ ! " & # $        %  #     %     &    " &    § ! $ § # ¤    #  &   ¤ ! ¦   ¥ $ ! ¦  ¡ ¥ $   "  ¤ % $ £  #  $    !   %     # %     # %  %  ' & § # # $     ( ¤   (  #  § ! $ § # ¤  %  % $   ¨      ¨ #   ¨ 0   ! "       ©  ¨  ¨    ¨  "   !  $     "   & ¨ '  " @ %  ¨   "  # &  © ¨ (      " 0     6  "   &    " &   '    ¨ #  "   ¨  ¨ A $    ¨ !   "    " &   ¨ # 6 0 "  A "  $  " & $ ' " "  !  ¨    "    $ ¨  ¨ 0  ¨   0 ¨ #  AC  "   " $    #  ¨ © " $ ¨ ¤ !  "  ¤ & #  $   & # $  %   % $ % (      (  %         %  #   # %     # % ¤ #      %     &      &    ! $ & #  $   & # $    %  ¨  $  §      ¤   (  ¥ &   #   &  '  ¦  &  %    ¨  %  (  '   &     %    ' &      $   $    !   %  #    #§  #   &  '  ¦     ( ¨  $     # ¤  !  %      &  "   ( # § %      $ &        (   § # # $  %  &  %     &  " &    ( #§       ( % ¤ #     %  !      (  %  &  %    ¤   (   # %    # %  # %  %     &     (  %  Convection Radiation % ' & ¥   ( #§  ¦ ¤ #      ( ¨ &  "  ¤ #$ ¦ " &  § # # $   $    !   %  #       ¤  ( ' &  ¥   " &        ' &   # ¤     § ! $ § # ¤ ¤   (  %  ¨  #% ¤ %   ¨ #  $     C ¡ $     6  ¨ 0 "   ¨ &  ¨  ¨ A A  ¨      ¨  © ¨     ¨   © ¨ #  A "  "   "    0 ¨  $ A "  ¨   )  ¦ &   '   "       &         % % $  % (        %  ¨   !  #§ $ &  §    ¤     #   "   § §  % ' ! #  %          §  # ¦  ! ¨   #  § !  &  " # # ' ¨§§  (      #  ¨      ¦ &     ¤  %  ' & ¥  ¤         ! $ ¤ #      ( #§       ¨        $ ! " & # $ §  ¤   %  ¤  #  #     " &      %  # "    § !  &  " # # ' §        " # #  ¤  %  % ' ! # %           % ' &  &   ¤      $ ! " & # $ §  ¤   %  % ' %    % §    §     ¨§      ¤  % ' ! # %    # ¤ &  $    % ( # %      Thermal Conductivity, k Heat current: k H= A= L= k= T2 - T1  "   "    0 A " $ $ ¨  ( & #  ¤  #  #     " &  & #  § !  &  $    ( #§    % §       ¤    %  ¨ §  "         $ ! " & # $ §  ¤   %  T2 T1   '  &    " &   ©  ¨ #  heat H=   ©  $ $ dQ kA = (T2 − T1 ) dt L dQ kA (T2 − T1 ) = dt L k ¡ B     $  " &      $ ¨ #  $   ¨ $ ¨   ¨   # &  # 0   $D ¨( " " £ 0 ¥  ¨ #  $  ¨ ©  $ ¨ #   "  $   '  &    " &   ©  ¨ #   " A %   ¨   '  ¨   $     ¨ $ ¨ #  6 $   $  ¨ @ ¨ ¨   ¨  ¨  " $   © ¨    ¨    # &    ! $  $    ' ¨ ( ¨  " ¨ &   ¤¡ ¢¡ 6    ¨   '  § £ ¨" E ¨   $    ¨ # § % ¨# ¡  " A $      "    '  ¨  6  #   ¨ #   " $    ¨ #       "  ¨ &   &   #  $    ¨ '  #  $  © k SI Units for Thermal Conductivity k H= kA (T2 − T1 ) L ° k E ¨" ) § ¨ ¡ £ ¨          '       "   § §  (      $    !   #   #§ %  (  $   ¦ # &   # § ¨ ( #§    ¤    #   & !  &   ! # ' &     "       '   &  §  &    &   #  & ! # ¤   %  ' &  &   ¤  & #    "   $    & '  ¤ #   $  §   #  !   ! #   ( #      ( # §  %   #   §   ! § #  ¦  #     '  " # ¦ ' &     "    %     #§ $  %    %    # ¢  #   ( #  ¥ ¤ £  %  #  §  & #  #  #   " &       $    !   %  #  §  & #  #  #      ( # ¢ "&" ¨   %       $    !   #  & ! # ¤   %  & # " &  ! &  §  ¡ &  ¨ "  ¦  #  ¦   # "  " &       '   &   #  & # "   ¥  # ( % $ % (        %        ( #  § §  $  CPS question A chair has a wooden seat but metal legs. The chair legs feel colder to the touch than does the seat. Why is this? E. The metal has a lower thermal conductivity than the wood. D. The metal has a higher thermal conductivity than the wood. C. The metal has a lower specific heat than the wood. B. The metal has a higher specific heat than the wood. A. The metal is at a lower temperature than the wood. Radiation: Power & Temperature ¥ ¨  !   ! #   ( #      & #     "     ¤   $   ¦ #  # %  % $  % (        %  H e: emissivity (dimensionless number between 0 and 1) σ: Stefan-Boltzmann constant = 5.67x10-8 W/m2K4 & #    "  ¥  # H = Aσe T (§ & &  ¤ ¦ § § #& £ )   !      ¤     !§ #  ¦  §  $    "  ¤   ¡  " # ¦  %  & # H ¥ ¤£ ¢¡ 7  "     ¨    !§  ¨ 1  &  1  (  ' 0  ) ¨ §  (  §      !   ¨    §   '  "    ¨        Radiation and Absortion H 6 5 432 #  ¨  ¨ & § &   ¨ §   & %   "    §         §  © ¨ § ¦ H # " &    7  & %   § ( "    $ #  "  = Aσe (T -T ) ¦ ¦ T env: Temperature of the environment surrounding the body ...
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This note was uploaded on 12/08/2010 for the course PHYSC 1220 taught by Professor Feiguin during the Fall '10 term at Wyoming.

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