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Homework Help: Two moving objects; 1D; constant

  1. Jan 31, 2013 #1
    1. The problem statement, all variables and given/known data
    2 objects A and B.
    A has a 4000 m. head start on x axis heading to the right
    Va = 50 m/s;
    Vb = 55 m/s
    aa = 0.5 m/s2
    ab = 1.0 m/s2

    need to know t in s when xa = xb

    2. Relevant equations

    r = r0+vt-a(t2/2)

    3. The attempt at a solution
    I set each up for xa,b in said equation and set them equal to each other.
    I plugged and chugged to a quadratic equation and ended up with a horrible answer of 140.04 seconds which makes no sense and then the other answer was negative
  2. jcsd
  3. Jan 31, 2013 #2

    rude man

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    Homework Helper
    Gold Member

    I don't think that equation's relevant! (It represents the height of something tossed straight up at initial height r0 with initial velocity v if a = g = 9.81 m/s^2.)

    Try to change the sign of the at^2/2 term?
  4. Feb 1, 2013 #3
    Yeah so close....but yet so far. Thanks
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