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Homework Help: Homework question, need help asap, please

  1. Jan 24, 2008 #1
    1. The problem statement, all variables and given/known data

    In an old-fashioned amusement park ride, passengers stand inside a 3.0-m-tall, 5.0-m-diameter hollow steel cylinder with their backs against the wall. The cylinder begins to rotate about a vertical axis. Then the floor on which the passengers are standing suddenly drops away! If all goes well, the passengers will “stick” to the wall and not slide. Clothing has a static coefficient of friction against steel in the range 0.60 to 1.0 and a kinetic coefficient in the range 0.40 to 0.70.

    2. Relevant equations

    T = 1/f

    and so the people dont slide

    (coefficient of friction) (Fn)= mg

    ( (coefficient of friction)*m*v^2)/ r = mg

    3. The attempt at a solution

    (coefficient of friction) = (g*r)/ (v^2)

    T = (2*pi*r)/ square root of ((g*r)/(coefficient of friction))

    and f= 1/T

    I got 0.4068 = f
    but the program says I am wrong
  2. jcsd
  3. Jan 24, 2008 #2


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    Staff: Mentor

    What did you use for the coefficient of friction? What did you use for the radius?
  4. Jan 24, 2008 #3

    Doc Al

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    Staff: Mentor

    Assuming that the question was to find the minimum frequency to insure that they wouldn't slide, it looks OK to me. How was the question phrased exactly?
  5. Jun 18, 2009 #4
    The 0.4068 is rotations in a second. You had to multiply that value by 60 to put it into rotations per MINUTE.
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