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Homework Help: Three Forces

  1. Feb 22, 2012 #1
    1. The problem statement, all variables and given/known data

    Three forces in the x-y plane act on a 2.6 kg mass: 13.3 N directed at 65°, 7.6 N directed at 160 °, and 10.1 N directed at 236° . All angles are measured from the positive x-axis, with positive angles in the Counter-Clockwise direction. Calculate the magnitude of the acceleration.

    2. Relevant equations
    Fx = m*ax
    Fy - m*ay
    Newton's Second Law in the x and y direction, respectively.

    3. The attempt at a solution
    I drew a picture on a scratch piece of paper, calculated x and y components of each vector, and then added x and y components of the resultant. Solving for acceleration, I got ax = 1.688 m/s^2, and ay = 7.808 m/s^2.

    How do I get the magnitude of the acceleration? Sorry for not being able to post my picture.
  2. jcsd
  3. Feb 22, 2012 #2


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    Homework Helper

    You can probably add those two components - the reverse of the was you calculated the components of each Force.
    Personally, I would have combined the final two components of the force to get a single net Force and then used F = ma, but it should give the same answer.
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