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Homework Help: Force under a graph

  1. Oct 9, 2008 #1
    1. The problem statement, all variables and given/known data
    337713766.jpg

    a) What is the work done by the force from x = 0 to x = 2 m?


    2. Relevant equations
    Work = Integral of Force Dx


    3. The attempt at a solution
    I was told since the equation for Force is not given, my best bet is to count the boxes under the curve from x=0 to x=2. I counted a total approx. of 20.4 boxes = 20.4J am I doing something wrong?
    Thanks for helping.
     
  2. jcsd
  3. Oct 9, 2008 #2

    Hootenanny

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    Is each box equivalent 1J?
     
  4. Oct 9, 2008 #3
    Y axis is measured in Newtons
    X axis is measured in meters

    isn't 1 full box, is a Newton*Meters = 1 J?
     
  5. Oct 9, 2008 #4

    Hootenanny

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    Look at the scale on the graph.

    How many increments per meter? How many increments per Newton?
     
  6. Oct 9, 2008 #5
    Oh, is .25m increment for x axis and .5newton increment for y axis.

    If I counted to be approx. 20.4 boxes
    How would I calculate the work?

    Or I should do each box?
    say first .25m is .5n * .25m and
    .50m is .50m * 1n?
     
  7. Oct 9, 2008 #6

    Hootenanny

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    First work out how much each box is worth (i.e. 0.25*0.5 Joules) and then multiply this by the total number of boxes.
     
  8. Oct 9, 2008 #7
    Thanks Hootenanny!
    Time to start cracking on those graph problems.
     
  9. Oct 9, 2008 #8

    Hootenanny

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    No problem :smile:
     
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