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Homework Help: Thermal Expansion Aluminium Problem

  1. Jan 14, 2012 #1
    A brass ring of diameter 10.00 cm at 19.9°C is heated and slipped over an aluminum rod of diameter 10.01 cm at 19.9°C. Assume the average coefficients of linear expansion are constant.
    (a) To what temperature must the combination be cooled to separate the two metals?



    Brass=19 x 10^-6
    Aluminum=24 x 10^-6

    (Change)A=γ x Ao x (change)Temperature.

    This is the equation for one instance.

    What is a conveniant equation to solve for both at the same time? I am stuck and I feel if I keep using that top equation I will just be guessing all day.
     
  2. jcsd
  3. Jan 14, 2012 #2
    I came across a equation that works, but I am not sure with the theory behind it..maybe someone can explain it for me.

    T= Initial temperature - (10.00-10.01)/[(10x19-10.01x24)10^-6]

    Proofing equations is probably my weakest area in academia.
     
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