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Power output

  1. Feb 6, 2010 #1
    1. The problem statement, all variables and given/known data
    Calculate the power output of a 1.8-g spider(the black dot) as it walks up a windowpane at 2.3 cm/s. The spider walks on a path that is at [tex]25^{o}[/tex] to the vertical as illustrated below.

    http://img19.imageshack.us/img19/4107/spiderl.jpg [Broken]

    2. Relevant equations
    P = W/t
    F = mg

    3. The attempt at a solution
    P= W/t = Fd/t = Fv cos [tex]\theta[/tex] = mgv cos 25 = (0.0018 kg)(9.81 m/s^2)(0.023 m/s) cos25 = 0.00037 W.

    Is this correct?

    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Feb 6, 2010 #2


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    Homework Helper

    While calculating the power you have not considered the angle given in the problem.
    So W = F*v*cos(theta)
  4. Feb 6, 2010 #3
    I have actually just editted my post after realizing this.
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