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Conduction heat transfer mechanisms

  1. Dec 8, 2008 #1
    1. The problem statement, all variables and given/known data[/b
    the ends of a 20cm long,2cm diameter rod are maintained at 0degrees and 100degrees by immersion in an ice-water bath and boiling water. heat is conducted through the rod at 4.5x10^4J/h. of what material is the rod made?

    2. Relevant equations


    3. The attempt at a solution

    i first changed the heat energy conducted into watts which is = J/s


    then i found the surface area of the rod


    now plug it into Q/dt=k(A/L)dT


    with this number i found that the rod is made of ice which has a k value of 1.7 (the closest number) but i checked the back and it suppose to be iron which has a k value of 80.. what did i do wrong?
  2. jcsd
  3. Dec 8, 2008 #2
    Your area is incorrect:
    A in this equation is the cross sectional area of the conducting rod... not the entire surface area.
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