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Homework Help: Physics Motion Help

  1. Feb 13, 2006 #1
    I'm having trouble with the 2nd part of this question, which asks at what instant the VAN (Green) overtakes the CAR (Red). I drew out the diagram. From what I believe, the displacements have to be equal so would I have to substitute two equations in each other?

    http://img371.imageshack.us/img371/4530/diag2nj.png [Broken]
     
    Last edited by a moderator: May 2, 2017
  2. jcsd
  3. Feb 13, 2006 #2
    That's correct

    marlon
     
  4. Feb 13, 2006 #3
    I'm just lost on how to start the question...my friend and I are discussing it but bleh >_<
     
  5. Feb 13, 2006 #4
    Well write down the equation of v as a function of time t.

    You know that :
    (30,15) and (0,0)
    (60,20) and (0,0)

    are the couples of points that belong to each linear curve.

    Can you write down the equation of a linear function when these points have been given ?

    marlon
     
  6. Feb 13, 2006 #5
    well we're not supposed to use linear function...it's on agraph so it displacement would the area underneath the graph...still stuck on it.
     
  7. Feb 13, 2006 #6
    i don't think you are getting the point.

    Just set up v = a*t

    by using [tex]y-y1 = \frac{y2-y1}{x2-x2}(x-x1)[/tex]

    The (x1,y1) and (x2,y2) have been given. Keep in mind that x is t and y is v here

    Or you can indeed get the a by calculating the surface under the curve.

    Anyhow, the result must stay the same.

    marlon
     
  8. Feb 13, 2006 #7
    Omg I Figured It Out. Thank You Marlon!
     
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