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Homework Help: Lab report graphs help

  1. Sep 18, 2010 #1
    1. The problem statement, all variables and given/known data
    I have to do a lab report on centripetal force, frequency and radius. My question is, does a graph have to show the (0,0) points? Also, I got an equation out of the graphing software for one of the graphs and it was y = 1.51x^0.4233, is it okay to use this equation or y = ax^b?


    2. Relevant equations
    y = ax^b
    y = 1.51x0.4233


    3. The attempt at a solution
    None
     
  2. jcsd
  3. Sep 18, 2010 #2

    rock.freak667

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    What are you plotting on the graph? Once the axes are labeled, you don't necessarily have to point out (0,0).
     
  4. Sep 18, 2010 #3
    I'm plotting Frequency vs radius for a constant centripetal force. Also, the graph has an exponential relation; frequency is exponentially proportional to the radius. But, the graph is going downards, not upwards. So, how do I state the proportionality? Here is the equation:

    y = 36.86 x^-0.7429
     
  5. Sep 18, 2010 #4

    rock.freak667

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    36.86 is a constant so you can just say that y∝x-0.7429
     
  6. Sep 18, 2010 #5
    Like this?

    Table 2 shows that frequency decreases with radius. A plot of the frequency vs. radius from the data in Table 2 is drawn in Graph 2. The shape of this graph suggests that y ∝ x-0.7429. The software shows that the curve that best fits the data is given by y = 36.86 x-^0.7429.
     
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