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Percent error and vectors

  1. Jun 26, 2011 #1
    1. The problem statement, all variables and given/known data

    What will happen to the percent error of graphical or force table method as the number of vectors to be added increases? Give proof.

    3 vectors
    A = 400 g
    B = 450 g
    C = 427 g

    2. Relevant equations

    3. The attempt at a solution

    First, I computed for the percent error of 2 vectors. I used vectors A & B:

    % error = [(400 - 425)/425] x 100 = 5.88%

    Then, I computed for the percent error of 3 vectors:

    % error = [(400 - 425.67)/425.67] x100 = 6.03%

    I concluded that as the number of vectors to be added increases, the percent error also increases. I'm not really sure about my answer.
  2. jcsd
  3. Jun 26, 2011 #2


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    Science Advisor
    Homework Helper
    Gold Member

    I am not sure what you are doing, you seemed to have taken an average of two or three numbers and then compared the first with the average? This is not correct. The percent error is the
    ((experimental value determined from the graph or force table - theoretical value determined from calculations)/theoretical value)) times 100 , or,

    % error = 100(Experimental - Theoretical)/Theoretical.

    The theoretical value is always the same. What about the experimental value as you increase the number of vectors in a given experiment?
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