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Rotational energy

  1. Mar 25, 2008 #1
    Three point masses lie along a rigid, massless rod of length L = 5.61 m :

    - Two particles, both of mass m = 2.1 kg, lie on opposite ends of the rod.
    - Mass M = 7.29 kg is in the center of the rod.

    Assume the rod lies along the x-axis, and rotates about the y-axis. about a point 1.28 m from one end at constant angular speed ω = 5.38 rad/s.

    Find the kinetic energy of this system

    could someone explain the ( about a point 1.28m from one end) . dose the distance 1.28 contribute any Kinetic energy to the system?
    thank you so much
  2. jcsd
  3. Mar 25, 2008 #2

    Doc Al

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    Staff: Mentor

    Use the distance from the axis of rotation and the angular speed to find the linear speed of each point mass. Use that to find their kinetic energy.
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