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Homework Help: Motion in one dimension problem

  1. Sep 19, 2009 #1
    1. The problem statement, all variables and given/known data

    An unmarked police car traveling a constant 85 is passed by a speeder. Precisely 1.00 after the speeder passes, the police officer steps on the accelerator. If the police car accelerates uniformly at 3.00 and overtakes the speeder after accelerating for 5.00 , what was the speeder's speed?

    2. Relevant equations

    vf = vo + at
    avg velocity = (vf + vo) /2
    d = vo)t + (1/2) at2
    vf2 = vo2 + 2ad

    3. The attempt at a solution

    I found that t=1s, a= 23.6 m/s2.. I am unsure what formula to use
  2. jcsd
  3. Sep 19, 2009 #2

    Andrew Mason

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    Science Advisor
    Homework Helper

    Draw a distance time graph for the police car. Let the time the speeder passes the police car be the origin. At t=6, what is d?

    Now you can draw the graph for the speeder. What two points do you have for the speeder's graph? What kind of graph is it? What physical quantity does the slope relate to?

    BTW, what units of distance are you using? 85 m/sec is about 200 mph.

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