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Homework Help: Vector Kinematics

  1. Jan 24, 2007 #1
    Problem:
    A particle starts from the origin at t=0 with an initial velocity of 5 m/s along the positive x axis. If the acceleration is -3i + 4.5j m/s^2 determine the velocity and position of the particle at the moment it reaches its maximum x coordinate.

    Possible equations:
    x= xo + vxo t + .5ax t^2

    I guess I'm just confused on how to start. I do not think I plug numbers into an equation yet. Do I need to work with the numbers I have before using an equation?
    Thanks for any help
     
  2. jcsd
  3. Jan 24, 2007 #2
    You have a couple options. Find the angle that the acceleration vector is at, and use a coordinate transformation so that the acceleration travels in the e_x direction (this way is sort of roundabout and I wouldn't really suggest it, but thought I would throw it out to get you thinking). Or find the separate components and add them together.

    Do you know calculus?
     
  4. Jan 24, 2007 #3
    Am I just adding the components of the acceleration and the velocity? Would that give me my endpoint?
     
  5. Jan 24, 2007 #4
    So I would focus on the e_x components first. Find what the maximum position will be in the e_x direction; determine how far the particle can go in the x direction with that initial push before it turns around. Then you can figure out what the e_y components are from the information in the e_x components.
     
  6. Jan 25, 2007 #5
    I have figured it out.

    Thanks for all your help
     
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