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Kinematics - acceleration in a straight line

  1. Sep 21, 2008 #1
    A car starts from rest and accelerates at a constant rate in a straight line. In the first second, the car covers a distance of 2.0 m. How fast will the car be moving at the end of the second second?

    Xo(1) = 0
    X(1) = 2.0 m
    Vo(1) = 0
    V(1) = 2.0 m/s
    t(1) = 1.0 s

    Thus, V(1) = Vo(1) + a(1)*t(1)
    a(1) = V/t
    = (2.0 m/s)/1.0 s
    = 2.0 m/s^2

    Since constant velocity,

    Vo(2) = 2.0 m/s
    a(2) = 2.0 m/s^2
    t(2) = 1.0 s

    V(2) = Vo + at
    =2.0 m/s + (2.0m/s^2)(1.0 s)
    = 4.0 m/s

    Can anybody confirm or refute this please?
  2. jcsd
  3. Sep 22, 2008 #2


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    Staff Emeritus
    Science Advisor
    Gold Member

    Re: Kinematics

    The question says the car covers a distance of two metres, not has a speed of 2m/s.
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