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Simple Acceleration and Velocity Problem

  1. Sep 5, 2008 #1
    1. The problem statement, all variables and given/known data
    A train travels along a straight track. Its position is given by x(t) = At^3 + Bt from t = 0 to t=5.0 s.
    a- find an expression for the velocity.
    b- find an expression for the acceleration.
    c- if the train has an acceleration of 2.00 m/s^2 and a velocity of 10.0 m/s at t=5, find 'A' and 'B'.


    2. Relevant equations

    v= dx/dt

    a = dv/dt

    3. The attempt at a solution

    I got 3At^2 + B for velocity and 6At for acceleration. I got (1/15) for 'A' and 5 for 'B'. I don't have a book yet and just wanted to make sure i understand what I'm doing. Any help would be appreciated!
     
  2. jcsd
  3. Sep 5, 2008 #2

    Kurdt

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    Looks good to me.
     
  4. Sep 5, 2008 #3
    Sorry, I don't know what you mean...
     
  5. Sep 5, 2008 #4

    LowlyPion

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    No you did it right. I made a hasty math mistake.
     
  6. Sep 5, 2008 #5
    Great. Thanks for your help!
     
  7. Sep 5, 2008 #6

    Kurdt

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    I'm saying your answers are correct. :smile:

    EDIT: methinks I missed something here :uhh:
     
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