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Homework Help: Simple question about spring constant

  1. Nov 5, 2006 #1
    I received a spring constant on the problem below to be .005 N/m.

    I was wondering if this was even possible? When I got the frequency in the next part of the question, the frequency made sense, but i never thought a spring constant could come out to be so small.

    A small fly of mass 0.13 g is caught in a spider's web. The web vibrates predominately with a frequency of 1.0 Hz.

    (a) What is the value of the effective spring constant k for the web?

    (b) At what frequency would you expect the web to vibrate if an insect of mass 0.54 g were trapped?

    So is .005 N/m an acceptable spring constant? Thanks to anyone who responds.
  2. jcsd
  3. Nov 5, 2006 #2


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    Any spring constant is possible. It appears you have done the calculation correctly.
  4. Nov 5, 2006 #3
    ah it's not right! here's my work:

    omega = 2pi f

    omega = 6.28 rad/sec

    omega = rad(k/m)

    6.28 = rad(k/.00013)

    k=.005 N/m

    i apologize for not using latex, but I do not know how to input omega and whatnot into it. Please help me with this problem!
  5. Nov 5, 2006 #4


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    Why do you think it is not right? You could go out another decimal place to get more precision, and should since you were given 2 significant figures in the data. Other than that it looks OK.
  6. Nov 5, 2006 #5
    No but, I entered it in Webassign and it told me it was not correct. The answers in web assign should be to 3 sig figs. Do you know what I am doing wrong?
  7. Nov 5, 2006 #6
    can anyone help me with this problem pleasee? It's the last one I have on my webassign, I need a 100! thank you
  8. Nov 5, 2006 #7


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    .005N is only 1 significant figure. If they are expecting three, you need to give them 3.
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