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Homework Help: Angular velocity acceleration

  1. Mar 14, 2007 #1
    1. a solid sphere (I=0.4mr^2) of mass 1.5 kg and radius 15 cm moves down a 35 degrees incline 7m long. Assuming it started from rest, what is its angular velocity in rad/s at the bottom of the incline? a)71.27 b)32.25 c)49.98 d)61.69




    3.i tried by plugging in the values and trying to find the angular acceleration so i could use the L=I(angular velocity) equation; but my numbers just dont add up. pls guide me through the process

    thnx

    ty
     
  2. jcsd
  3. Mar 14, 2007 #2
    Use the principle of conservation of Energy. The gravitational potential energy is converted into Angular Kinetic Energy.
     
  4. Mar 14, 2007 #3
    The gravitational potential energy is converted into angular KE AND translational KE. Assuming that rolling without slipping happens here, you can use the relation v=rw to solve for the angular velocity.
     
  5. Mar 15, 2007 #4
    can someone pls provide me with a mathematical representation of the previous replies?

    or at least outline the steps that i will need to follow

    im a bit confused about all this

    thnx

    ty
     
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