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Homework Help: Centripetal Acceleration with Tarzan

  1. Feb 29, 2012 #1
    1. The problem statement, all variables and given/known data
    Tarzan plans to cross a gorge by swinging in an arc from a hanging vine, as shown in the figure.
    If his arms are capable of exerting a force of 1200 N on the vine, what is the maximum speed he can tolerate at the lowest point of his swing? His mass is 100 kg, and the vine is 4.5 m long.

    2. Relevant equations
    Tension force - mg = ma
    (a * r)^1/2 = v

    3. The attempt at a solution

    1400 N = (100 kg)(a)+(100 kg)(9.8m/s^2)
    420 N = 100kg * a
    a = 4.20 m/s^2

    (4.20 m/s^2)(2.25m)^1/2 = v

    Why is it incorrect to use 2.25 m as the radius? They gave the entire length of the vine.

    Attached Files:

  2. jcsd
  3. Feb 29, 2012 #2


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    Homework Helper

    If you look at the picture, what point is tarzan 'orbiting around' ?
  4. Feb 29, 2012 #3
    I lol'd

    The picture reminds me of a picture on one of the exams I did a while back in highschool, there's some bizarre half black half white basketball playing hybrid

    Also, what BruceW said

    Attached Files:

  5. Feb 29, 2012 #4
    Oh I see. That's more clear. He's orbiting around the very top of the tree, not the middle of the vine.
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