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Homework Help: Police Persuit Question (new)

  1. Feb 22, 2010 #1

    Monocerotis

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    Gold Member

    1. The problem statement, all variables and given/known data

    A police ar traveling a constant 90 km/h is passed by a speeder travelig 130 km/h. 1.00s after the speeder passes, the policeman steps on the accelerator. If the police car's acceleration is 2.00 m/s^2, how much time elapses after the police car is passed until it overtakes the speeder (assumed moving at a constant speed)



    3. The attempt at a solution
    This is my first encounter with these types of problems, at the level where I need to solve it without trial and error graphing.

    Could someone provide a bit of guidance because I'm not sure how to do this problem.
     
  2. jcsd
  3. Feb 22, 2010 #2
    What is the position of the speeder at time t.
    What is the position of the policeman at time t.
    for what t are they equal.

    motion with constant acceleration:
    [tex] x = x_0 + v_0 t + (1/2) a t^2 [/tex]

    motion with constant velocity
    [tex] x = x_0 + v_0 t [/tex]
     
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