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Homework Help: Vector Equillibrium Question

  1. Sep 9, 2008 #1
    1. The problem statement, all variables and given/known data

    I have four vectors arranged within a circle, with Vector A at 0 degrees with 1.47 N. Vector B is at 71 degree with 1.96 N. Vector C is at 152 degrees with 2.45 N. And Vector D is at 249 degree with 2.94 N.

    These vector are in Equilibrium. Calculate the resultant force in x and y components.

    This is a diagram of the Vectors

    2. Relevant equations
    Well, I know that in equilibrium, the resultant force in the x and y component of the vectors is at ZERO.

    I know that Fx is Calculated by Fx = (Force)(Cos ANGLE) and Fy = (Force)(Sin ANGLE)

    What I need to find is the sum of all those vectors and have them as close as possible to zero, and find how much error there is.

    3. The attempt at a solution

    Basically, I tried to sub all my numbers into Fx = (Force)(Cos Angle) to find the X- components.

    I found these numbers getting very weird....

    And I am not sure after getting all these individual numbers whether to add them or to subtract them.

    This is the same problem I have with calculating the y-component.

    I am not sure if I am using the right angle...cause the only angles I am using in my equations are, 0, 71, 152, 249 degrees.

    And In the end, in finding the both x and y, would adding or would subtracting them be the way to find the resultant x & y? I know that it should be Zero.

    Attached Files:

  2. jcsd
  3. Sep 9, 2008 #2
    So could anyone point me along a direction or something to work on?

    We're just learning vectors and I am finding this extremely confusing.

    Any help is appreciated...
  4. Sep 9, 2008 #3


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    Homework Helper

    Remember that with vector equations direction is important, even when you have broken them into components. When you resolve your vectors into components you must be sure to carry the right sign. For your equations though, they have asked you to calculate the resulting vector, which you are calling the error vector. Just go where the data goes, as long as you have taken care to use the right sign for each.
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