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Homework Help: Motion with Constant Acceleration help!

  1. Feb 7, 2010 #1
    1. The problem statement, all variables and given/known data
    Two cars drive on a straight highway. At time t = 0, car 1 passes mile marker 0 traveling due east with a speed of 18.0 m/s. At the same time, car 2 is 0.90 km east of mile marker 0 traveling at 30.0 m/s due west. Car 1 is speeding up with an acceleration of magnitude 0.40 m/s^2, and car 2 is slowing down with an acceleration of magnitude 0.80 m/s^2.

    2. Relevant equations

    I have used that data to create an X vs T equation
    x1=(18.0 m/s)t+(0.2)t^2;\;x2=900 m -(30.0 m/s)t+(0.4)t^2

    3. The attempt at a solution

    I cannot show an attempt because i have searched in the book how to find where they meet and am unsuccessful. Can anyone tell me how to figure this out starting from the beggining? Thank You!
  2. jcsd
  3. Feb 8, 2010 #2


    User Avatar
    Science Advisor
    Homework Helper

    You seem to have been careful with the signs, and your equations look correct.

    If you set x1 = x2, you will find the time instant at which they meet.
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