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!

Angular Velocity?

  1. Mar 12, 2007 #1
    Angular Velocity????

    A thin uniform rod is rotating at an angular velocity of 9.37 rad/s about an axis that is perpendicular to the rod at its center. As the figure indicates, the rod is hinged at two places, one-quarter of the length from each end. Without the aid of external torques, the rod suddenly assumes a "u" shape, with the arms of the "u" parallel to the rotation axis. What is the angular velocity of the rotating "u"?

    Before: The system is a single rod of mass M and length L rotating about an axis through its center.
    After: The system consists of three parts; a rod of mass M/2 and length L/2 rotating about an axis through its center and two masses M/4 rotating at a distance L/4 from the axis. (Treat these masses as particles.)



    I know I should use the conservation of momentum, moment of inerta for the rod, Net torque= Inertia x angular acceleration but I have no idea where to start!!!

    Help me exam tomorrow!!!
     
  2. jcsd
  3. Mar 13, 2007 #2

    Galileo

    User Avatar
    Science Advisor
    Homework Helper

    Indeed, conservation of momentum is the way to go.
    The momentum before is [itex]I_1\omega_1[/itex] and after it's [itex]I_2\omega_2[/itex].
    So ask yourself what's given, what can you calculate and what is the unknown?
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Angular Velocity?
  1. Angular velocity (Replies: 2)

  2. Angular Velocity (Replies: 9)

Loading...