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Force required on Axel

  1. yes

    1 vote(s)
  2. no

    1 vote(s)
  1. Apr 1, 2004 #1

    This will be a very simple questions for all you pro's out there.
    I want to know the amount of horsepowers required to start the rotation and maintain a rotation of 20 RPM of an axel which has an arm of 4 mts having a load of 100 kgs at the end of the arm.

    the dia of tha axel is 1000mm (10 Cm.) and the leangth of the arm as stated above is 4 meters.

    Please help
  2. jcsd
  3. Apr 1, 2004 #2


    User Avatar
    Science Advisor

    Technically the answer is 0.

    The only thing reason the system will need power to keep it going is because of friction, a variable you don't know.
    For a second I thought (mv^2)/r would have something to do with it but that force is exerted by the 4m bar and not a motor connected to a shaft.

    If you give a required torque specification for that given RPM, I can tell you how much power you need.

    btw, I voted no.
    Last edited: Apr 1, 2004
  4. Apr 1, 2004 #3
    The final speed isn't important - what you need to decide is the rate at which your device (which sounds more like a centrifuge than an axle) gets to that speed, i.e the (angular) acceleration. Once it's up to speed you just need to overcome friction losses, etc to keep it there.
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