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Homework Help: Spring force sensor help

  1. Sep 8, 2008 #1
    1. The problem statement, all variables and given/known data
    A spring has a force sensor attached to it and is pulled at increasing distances from rest. A reading is recorded on the force sensor and the data is plotted below.
    Plot data on Excel
    x (m) Force (n)
    .005 1.9
    .010 2.5
    .020 3.4
    .030 4.2
    .040 5.3
    .050 5.6
    .060 5.8
    .070 6.6
    .080 7.1
    .090 7.5

    (Basically he made us plot these numbers in excel then predict k and stuff then we did =ln( and found the natural log on excel i believe to make a straight line??)

    a. Based on the graph of the raw data predict a relative k (less than 1 , about 1 , greater than 1) and explain your prediction

    I put since that line is above the coordinate 1,1 K is greater than 1

    b. Predict an exponential and provide a justification for your prediction.

    I put the exponential seems to be lower than 1 because the line has a small decline in the middle.

    c. Create a second graph to determine your exponent and calculate a spring constant.
    I'm guessing this is the natural log graph but what is spring constant???? by using y = mx +b i found for y=k (x to the nth power) to be n = .4838 and k= 23.686

    d. Create another graph of y vs. x to the nth power now that you know your n value and verify your k. Place this graph on paper.

    Now im totally lost maybe you can help me out here. Remember this is my 3rd DAY in Hon Physics. Feel my pain!

    e. If a normal spring requires a force to extend the spring that is directly proportional to the distance extended, is this a normal spring? In other words, if it was a normal spring what should we have seen when we plotted a graph of the raw data?

    I am totally lost here too

    2. Relevant equations

    3. The attempt at a solution
  2. jcsd
  3. Sep 8, 2008 #2


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    Homework Helper

    Re: Spring

    Welcome to PF.

    They are asking you to make a graph whose x dimension is in units of (x)n.
    You should expect that if you plotted y = k*(x)n with your calculated n, you will get a straight line that is slope 23 from your data?

    As to part e wouldn't what they are asking really be if you plotted it on a regular (x)1 axis that the locus of data points would be a straight line?
  4. Sep 9, 2008 #3
    Re: Spring

    Yeah for part e. he was asking if it was a straight line or not and the slope was 23. Thank You for your help
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