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Rotational Forces on a Hollow Cylinder

  1. Oct 21, 2015 #1
    1. The problem statement, all variables and given/known data
    I am trying to model a hollow cylinder of known radius r, length l and density rho.
    The cylinder is fixed on a horizontal axle along its longest axis (l) and will have a force F applied tangentially to its surface and perpendicular to its axis, with negligible frictional forces acting between it and the axle.
    What equations could I use to model the speed of its rotation?

    2. Relevant equations
    Mass = pi*r2*l*rho
    Some equation involving moments, potentially?
    I am a mathematician and have little work on angular velocity, so I apologise for the trouble.

    3. The attempt at a solution
    I have attempted to find a relevant equation but all searches gave either inapplicable scenarios or equations quoted ad verbatim with no clarification to notation.
     
  2. jcsd
  3. Oct 21, 2015 #2

    haruspex

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    Do you know about moment of inertia... how it is defined, the formula for the MoI of a cylinder, its use in angular acceleration...?
     
  4. Oct 21, 2015 #3
    Okay, so I have found the equation I = MR^2 for a cylindrical shell of negligible width being rotated along its long axis, which is close to what I'm looking for. However, I would not know how to include such an equation in finding angular acceleration.
     
  5. Oct 21, 2015 #4

    haruspex

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    It's very like the linear equation: torque about axis = moment of inertia about axis * angular acceleration about axis.
     
  6. Oct 22, 2015 #5
    That's perfect, thanks!
     
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