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Calculating Air Resistance

  1. Nov 16, 2012 #1
    1. After dropping coffee filters, I have to derive or describe the relationships between air Resistance(R) and v or v^2, whichever is right, and draw a graph. I can find derivations on internet as long as I site.
    I have time, v, height and acceleration, but no reference area. All the equations I've seen need the ra, is there any way I can find R without it?

    2. v=m/s
    a= v/s = m/s^2
    Net F = R-w
    w=mg
    D = Cd * r * V^2 * A/2

    3. When the object reaches terminal v, a=0. So I put 0 for a= (W - D)/m that I also got from the internet, but I got something useless with m/s units(supposed to be in N because R is a force). I don't know what I'm supposed to do!
     
  2. jcsd
  3. Nov 16, 2012 #2

    CWatters

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    Rearrange..

    0 = (W - D)/m

    to give..

    W = D

    You can measure W.

    Plot V or V2 against W (=D) and see what you get.
     
  4. Nov 16, 2012 #3

    CWatters

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    PS Try to ensure the filters stay the same shape as they fall, eg don't add too much weight.
     
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