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Homework Help: Aluminum wire, current, voltage, density, find mass

  1. Mar 9, 2005 #1
    An aluminum wire is hung between two towers and has a length of 175 m. A current of 125 A exists in the wire, and the potential difference between the ends of the wire is 0.300 V. The density of aluminum is 2700 kg/m3. Find the mass of the wire

    I have no idea how to do this :'(
     
  2. jcsd
  3. Mar 9, 2005 #2

    dextercioby

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    HINT:
    [tex] R = resistivity \ \frac{l}{S} [/tex]

    Daniel.
     
  4. Mar 9, 2005 #3
    Resistance [tex] R = s \frac {l}{A}[/tex] where s is the resistivity of Aluminum. Find the cross sectional area A using this equation. (R is found using ohm's law V = I*R)

    Well, knowing cross sectional area, length and density you can find the
    Mass.
     
  5. Mar 9, 2005 #4
    Sorry Daniel. I did not see your post. I was busy typing... :smile:
     
  6. Mar 9, 2005 #5

    dextercioby

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    Why do you appologize...?:bugeye:

    Daniel.
     
  7. Mar 9, 2005 #6
    vaxcopy are you in Frenrich's physics class in edmonton AB, i know how to do this question but i dont get the other ones if you are in her class. help?
     
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