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Homework Help: Principle of Moments

  1. Apr 21, 2010 #1
    1. The problem statement, all variables and given/known data
    A metre rule is balanced at the 50 cm mark. If a mass of 5kg is placed 40 cm from the pivot at one end, what mass must be placed 30 cm from the pivot on the other end to balance the rule?


    2. Relevant equations

    M1 * G * D1 = M2 * G * D2



    3. The attempt at a solution
    M1 = 5kg
    M2 = ?
    D1 = 40 cm
    D2 = 30 cm
    G = 9.8

    Therefore 5 * 9.8 * 40 = M2 * 9.8 * 30
    = (5 * 9.8 * 40)/9.8 * 30
    M2 = 6.66kg Is this correct?
     
  2. jcsd
  3. Apr 21, 2010 #2
  4. Apr 21, 2010 #3

    PhanthomJay

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    Yes.
     
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