1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Work / Moment of inertia

  1. Feb 20, 2008 #1
    1. The problem statement, all variables and given/known data
    A man is standing on a rotating plate (rotates without friction). In case A he is hold 1weight in each hand (straight out) with the mass m and he is rotatin with angular velocity omega_0.
    Then he moves his arms down so they are parallell to the body (case B) and increases his angular velocity to omega_1.
    Calculate the new angular velocity omega_1 and the work U which the man must do to change his body configuration to case B.
    You can assume that the moment of inertia on z-axis for the man is I_0 in case A and I_0 / 2 in case B.
    The length of the arms of the man is l, so each weight are l units out in case A and lowered l units (and ofcourse moved l units toward the body) in case B.

    the answers are given
    omega_1 = 2 omega_0
    and
    U = 0.5*I_0*(omega_0)^2 - 2mgl


    My Problem is i get how to calculate the angular velocity omega_1
    But I don't understand how to even start on calculating the work done.

    Best regards /Peter

    2. Relevant equations



    3. The attempt at a solution
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Can you help with the solution or looking for help too?
Draft saved Draft deleted



Similar Discussions: Work / Moment of inertia
  1. Moment of Inertia (Replies: 0)

Loading...