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Homework Help: Given force equation, solve for work.

  1. Mar 18, 2012 #1
    1. The problem statement, all variables and given/known data
    Assume that a force acting on an object is given by , where the constants = 2.9 and = 3.9 . Determine the work done on the object by this force as it moves in a straight line from the origin to = (10.0 + 21.5).

    3. The attempt at a solution
    well... what i did first was i found the length of the tangent of the distance. (using the pythagorean theorem, to get 23.7m).
    i dont really know what to do with the other given information. i thought maybe i could plug the given constants into the equation graph and then find the length of the tangent of the force (which i got to be 4.86 N) and then just plug into the equation W=FΔx, but that is incorrect.

    apparently the answer is roughly 1000 J, but im obviously not getting that as my answer.
  2. jcsd
  3. Mar 18, 2012 #2
    Hey,i think you missed writing the equation. the entire problem has not been provided
  4. Mar 18, 2012 #3
    hahahaha....oops sorry the force is given by the equation F=axi+byj (i, j being the components of the force i (hat) and j (hat)). the constants a=2.9 N/m and b=3.9 N/m
  5. Mar 19, 2012 #4

    See break force and displacement along the axis.
    Force along X axis is given by ax (i)
    Remember this force is not a constant and depends on the position of particle on x axis given by x.

    Displacement along x in moving from x to x +dx is given by dx (i)
    which makes dW=ax(dx).
    Integrate to get work

    Do similarly for y.

    What do you see?
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