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Homework Help: HELP System of particles problem

  1. Nov 8, 2008 #1
    HELP!!!System of particles problem

    1. The problem statement, all variables and given/known data
    A 10kg dog walks 3m on a 20kg boat towards shore. How much nearer the shore does the dog end up if the boat was initially at rest.



    3. The attempt at a solution
    I am not really sure how to approach this problem. I think that the dog is 3 meters closer to the shore, because the boat stays at rest while the dog moves toward the shore...yet I think this is wrong because it is too simple as a physics problem...

    Can anyone help me with this problem? thank you very much.
     
  2. jcsd
  3. Nov 9, 2008 #2
    Re: HELP!!!System of particles problem

    hey, here's how i solved this question...not sure if its right. I think we're in the same class

    Pi=Pf

    m1v1=m2v2

    v=d/t

    (m2= 20kg + 10kg because the boat and the dog are the same mass once the dog stops moving)

    10(3/t) = 30(d/t)

    The t's then cross out

    30=30d

    d=30/30

    d= 1.0m
     
    Last edited: Nov 9, 2008
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