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Homework Help: Center of mass

  1. Dec 9, 2007 #1
    1. The problem statement, all variables and given/known data
    Car A with mass 2400 kg is moving along a straight stretch of road at 45 miles per hour. Car B with mass 1100kg follows with speed 65 miles per hour. How fast is the center of mass of the 2 cars moving?

    2. Relevant equations
    Xcm=(M1X1+...+MnXn)/ (M1+...+Mn)

    3. The attempt at a solution
    hmm i did

    (2400kg x 45mph +1100kg x 65 mph)/ (1100kg+2400kg)= 51.3 mph
    But that seems a bit too easy..
  2. jcsd
  3. Dec 9, 2007 #2


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    Science Advisor
    Homework Helper

    May seem too easy, but that's no reason to mistrust it.
  4. Dec 9, 2007 #3
    hmm so was my method right?
  5. Dec 9, 2007 #4


    User Avatar
    Staff Emeritus
    Science Advisor

    Homework questions aren't meant to be a trick! If you've studied, and understand the material, then often you will find the problems quite straightforward.
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