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Homework Help: Kinematics using integration

  1. Jul 15, 2011 #1
    1. The problem statement, all variables and given/known data

    If an Airplane is to attain a take off velocity of 75 m/s after traveling 240 m along the flight deck of an aircraft carrier. Find the Aircrafts acceleration(asssumed constant)



    2. Relevant equations

    S=∫vdt
    V=∫adt

    V=75 m/s
    S=240m
    t(time)=0
    3. The attempt at a solution

    S=∫75dt
    = 75t + C
    240 = 75t + C
    240 = 75(0) + C
    C = 240
    S=75t + 240
    V=∫75t+240dt
    V=75t^2/2 + 240t

    Not sure what to do next or if I am even on the right track.
    thanks for any help
     
  2. jcsd
  3. Jul 15, 2011 #2

    SteamKing

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    Look at the problem this way: When t = 0, s = v = 0
    The plane then undergoes a constant acceleration a

    At time t = t2, the plane has velocity v = 75 m/s and has traveled s = 240 m

    Notice that the plane's velocity is not constant.

    Can you come up with a better set of equations than in the OP?
     
  4. Jul 15, 2011 #3
    Thanks for the nudge. This is the part I struggle with I guess I haven't learned the kinematic relationships very well.

    So, if velocity isn't constant then it has to be dependent on the time & displacement.

    Would a better equation be s = ∫240t?
     
  5. Jul 16, 2011 #4

    SteamKing

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    You're just guessing now.

    Start with the basics. v = ds/dt a = dv/dt

    Since you know a is constant, work with that equation first.
     
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