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Homework Help: Find displacement from a record of travel

  1. Sep 1, 2011 #1
    1. The problem statement, all variables and given/known data

    A record of travel along a straight path is as
    (a) Start from rest with constant acceleration of 3.95 m/s
    for 16.5 s;
    (b) Constant velocity of 65.175 m/s for the
    next 0.789 min;
    (c) Constant negative acceleration of
    −10.4 m/s
    for 3.52 s.
    What was the total displacement x for the
    complete trip?
    Answer in units of m

    2. Relevant equations

    I had my physics teacher help me along. I know that you need to find and add all of the displacements, but I still can't seem to get the right answer.

    3. The attempt at a solution
    I don't remember exactly what I did, but I got these numbers for the displacement for each section of the problem.
  2. jcsd
  3. Sep 1, 2011 #2


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    Homework Helper
    Gold Member

    Part (c) looks off. What did you do to get that answer? BTW, negative acceleration of -10.4m/s2 is a double negative.
  4. Sep 1, 2011 #3


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    Homework Helper

    Yes part (c) wrong. This body doesn't even stop by that time.

    With an initial velocity of 65, and an acceleration of -10, it will have merely slowed to 30 m/s. Use the real numbers to get the real answer.
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