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Homework Help: (UCM) Maximum Rev. Per Minute Using Length and Acceleration

  1. Feb 21, 2012 #1
    1. The problem statement, all variables and given/known data

    An astronaut rotates at the end of a test machine whose arm has a length of 10m. If the acceleration she experiences must not exceed 5g (g = 10 ms^-2), what is the maximum number of revolutions per minute of the arm?

    2. Relevant equations

    T = (2πR)/v

    V = (2πR)/T

    Ac = V2/r

    3. The attempt at a solution

    Ac = v2/r

    Plug in acceleration given and radius (from length of 10m): 10 = v2/5

    5*10 = 50

    50 = v2

    v = 7.07107

    T = 2π*5/7.07107

    T = 4.44288 revolutions for 1g

    Multiply 4.44288 by 5 = 22.2144 RPM?
    Last edited: Feb 21, 2012
  2. jcsd
  3. Feb 21, 2012 #2


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    Homework Helper

    Hi Oziemaster,

    Do you know what "g" is?

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