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Homework Help: Kinematics & Dynamics

  1. Oct 6, 2005 #1
    Object A travels at a constant velocity af 2.0 m/s east, and object B travels in the same direction at a constant velocity of 3.0 m/s. If object B starts 1.0 min after object A, how long (time) will it take object B to catch object A?
     
  2. jcsd
  3. Oct 6, 2005 #2
    You're dealing with constant velocity so you know [itex]d = vt[/itex] applies.

    Object A

    [tex]d_A = 2.0t[/tex]

    Object B

    [tex]d_B = 3.0(t + 1.0)[/tex]

    Because object B is going to catch object A, the distance will be the same. Can you take it from here?
     
  4. Oct 10, 2005 #3
    I don't quite get it, but this is what I tried:

    dB = 3.0(t+1.0)
    = 3.0t+3.0

    dA = dB
    2.0t = 3.0t+3.0
    -1.0t = 3.0
    t=-3.0

    but the answer key shows 1.2 x 10^2 s (2.0 min not -3.0 min)
    sorry, but i need more help.
     
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