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Homework Help: Energy, Thermal Expansion

  1. Apr 29, 2009 #1
    1. The problem statement, all variables and given/known data
    An aluminum rod is 23.0 cm long at 20°C and has a mass of 350 g. If 12500 J of energy is added to the rod by heat, what is the change in length of the rod?

    Answer is in mm

    2. Relevant equations
    Q=m*c*delta T

    3. The attempt at a solution

    The answer I get is 2.19*10-4m which is wrong
    That /1000 to get mm is 2.19*10-7 which is wrong

    I don't understand what I did wrong...
  2. jcsd
  3. Apr 29, 2009 #2


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    Homework Helper

    Isn't 2.19*10-4m = .219 mm?
  4. Apr 29, 2009 #3
    Whoops...divided instead of multiplied. Thanks.
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