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Train vs. Car

  1. Jun 25, 2010 #1
    A train is moving parallel and adjacent to a highway with a constant speed of 31 m/s. Initially a car is 49m behind the train, traveling in the same direction as the train at 43 m/s and accelerating at 3 m/s/s.

    What is the speed of the car just as it passes the train?

    Answer in units of m/s.

    Any help would be much appreciated. I have no idea where to start this so if you could lead me in the right direction with equations that would be great.
  2. jcsd
  3. Jun 25, 2010 #2
    Can you write some kinematic equations that describe the position of each object along a straight line in relation (as a function of) to time?
    It can be assumed that when we first look at these two objects moving they are in diff positions with possibly different velocities but we will begin our interest in both at what can be called t = 0s. Then, later on, they will have traveled the same amount of time when they are at the same position. So variables begin to fall out and we can solve for v for both objects.
    So equations?
  4. Jun 27, 2010 #3


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    Moderator's note:

    Please let the OP respond to pgardn's post -- to write the kinematic equations for uniformly accelerated motion, and put some more thought into working out the problem -- before providing further help.

    (Two posts that provided equations have been deleted from this thread.)

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