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Homework Help: Simple Problem

  1. Sep 28, 2009 #1
    http://img40.imageshack.us/img40/8591/ques.png [Broken][/URL]



    a(t)=dv/dt
    v(t)=dx/dt




    I thought it was just
    v(t)= (alpha)t^2/2 + w
    x(t)=((alpha)t^2)/6 + wt + a


    But the answer is ((alpha)t^2)/6 + wt + a - 2w - 4(alpha)/3

    Can someone please explain this to me...
     
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Sep 28, 2009 #2

    Delphi51

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    Homework Helper

    Starting from your v = .5*@*t^2/2 + W
    x is the integral dt of this: x = .5*@/3*t^3 + wt + k
    To evaluate the constant k, put in time 2 and x = A:
    This gives you k = A - 4/3@ - 2w
    Put that back in the x formula and you have the answer you are looking for, though there seems to be a t^2 instead of a t^3 in the answer.
     
  4. Sep 28, 2009 #3
    Thank you very much!
     
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