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Homework Help: Ball hitting block, elastic collision

  1. Dec 10, 2009 #1
    1. The problem statement, all variables and given/known data

    .500kg ball attached to a cord that is 70 cm long. ball strikes a 2.5kg block at rest

    what is the speed of the ball just before hitting the block
    and collison is perfectly elastic find speed of ball and block after collision

    2. Relevant equations



    3. The attempt at a solution
    Uo=MGY
    (.5)(9.8)(.7)= 3.43J
    Ko=0
    Uf=0
    J=.5(.5)v^2= 2.62

    part b
    2.62=V2f-V1f
    1.31=.5V1f+2.5V2f

    matrix on calc
    V1f= -1.75
    V2f=.87
     
  2. jcsd
  3. Dec 10, 2009 #2

    ideasrule

    User Avatar
    Homework Helper

    Re: Collision

    I don't understand the question. Do you have a diagram? How is the cord attached? Is it a spring or something?
     
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