Force required on Axel

what sort of poll is this i dont know

  1. yes

    1 vote(s)
    50.0%
  2. no

    1 vote(s)
    50.0%
  1. Hello,

    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. ShawnD

    ShawnD 986
    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. 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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