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Homework Help: Finding Center of mass

  1. Apr 23, 2008 #1
    [SOLVED] Finding Center of mass

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

    Three cubes, of side 0, 20, and 30, are placed next to one another (in contact) with their centers along a straight line as shown in the figure. What is the position, along this line, of the CM of this system? Assume the cubes are made of the same uniform material and 0 = 2.5 cm.

    2. Relevant equations

    Xcm = m1x1 + m2x2.../ m1 + m2 +....

    3. The attempt at a solution

    it does not give the mass of the cubes, so i dont know how to relate to such a problem
  2. jcsd
  3. Apr 24, 2008 #2


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    Science Advisor
    Homework Helper

    If they have the same density, then you may not know the masses, but you know the ratio of the masses. That's all you need to know. Assume any density you like and work it out. Now choose another density and work it out. You'll get the same answer.
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