Problem with Conductivity

  1. 1. The problem statement, all variables and given/known data

    A cylinder with a piston is filled with ideal gas. The gas temperature is held at 450 K. The cylinder is heated by an oven through a square metal rod connected between the oven and the cylinder. The rod has sides d = 1 cm and length L = 2.3 m.

    (a) If the oven is held at 750 K, and the heat current conducted through the metal rod is 27 W, find the thermal conductivity of the metal in the rod.

    k = W/m K
    9 NO

    HELP: H = k*A*(T2-T1) / L

    HELP: H is the heat current; k is thermal conductivity; T2 and T1 are temperatures at two ends; A and L are cross-sectional area and length of the rod.

    2. Relevant equations

    H = k*A*(T2-T1) / L

    3. The attempt at a solution

    27=k(.023m^2)(300k)/2.3m

    k=9

    I'm pretty sure im right here... the following quesion asks,

    For a larger cylinder at 450 K, a heat current of 57 W is needed. If we use the same metal rod to conduct heat, find the oven temperature in Kelvin that will maintain the necessary heat current.

    and i used the k value 9 and gave me an answer 1083.3, which was the correct answer...
     
  2. jcsd
  3. looks right.
     
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