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Need help with hard question

  1. Sep 6, 2011 #1
    The brakes on your automobile are capable of creating
    acceleration of 14 ft/s2. If you are going 82 mi/hr and sud-
    denly see a state trooper, what is the minimum time required to get your car to 55 mi/hr?

    How far do you travel while returning to the legal speed limit?
  2. jcsd
  3. Sep 6, 2011 #2
    You'll have to post where you're stuck at so we can provide the right direction. Just giving the answer won't help you in the long run.
  4. Sep 6, 2011 #3
    i don't know how to start the problem.
  5. Sep 6, 2011 #4


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    Last edited by a moderator: Apr 26, 2017
  6. Sep 6, 2011 #5
    You've been given acceleration, final velocity, and initial velocity, and are looking for time, right? Take a look at your equations of motion.
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