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Homework Help: Vector Kinematics

  1. Aug 28, 2010 #1
    A particle starts from the origin at t = 0 with an initial velocity of 5.0 m/s along the positive x axis. If the acceleration is (-4.9 + 2.9 ) m/s2, determine the velocity and position of the particle at the moment it reaches its maximum x coordinate.



    velocity i m/s + j m/s
    position i m + j m

    i am completely lost on this.
     
  2. jcsd
  3. Aug 28, 2010 #2

    s3a

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    When the height of release of a projectile equals the height of landing, the optimum angle is 45 degrees. The optimum angle basically is the angle at which you launch a projectile to cover the greatest horizontal distance. The velocity, V, in its components is Vx = Vcos45deg and Vy = Vsin45deg, in this case. Also i means horizontal and j means vertical.
     
  4. Aug 28, 2010 #3
    thanks for the help but thats not it. the I hat for V in the answer is 0. i can't determine the J hat or position vectors however.
     
  5. Aug 29, 2010 #4

    s3a

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    Sorry your question is a little unclear. Is the acceleration in i and j? Is the vertical height unknown? Is the vertical velocity unknown or just not mentioned?
     
  6. Aug 29, 2010 #5
    That's what I was thinking too. It seams as if there is not enough information present to solve the equation.
     
  7. Aug 29, 2010 #6

    s3a

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    It seems so but in case I'm wrong, in the future: you need either 3 known variables for one component or two known variables per two components then combine the equations.
     
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