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Water in the Bucket: Free Body Diagram? (Vertical Centripetal Force)

  1. Jan 6, 2009 #1
    Water in the Bucket: Free Body Diagram?? (Vertical Centripetal Force)

    1. The problem statement, all variables and given/known data

    If a bucket tied to a rope is revolving vertically in an counter clockwise direction, what would be the Free Body Diagram of "water" in the bucket at the top position?

    2. Relevant equations

    There are no equations

    3. The attempt at a solution

    I am guessing there would be two forces: gravitational pointing downward and contact force with the bucket pointing in the direction opposite to the motion of the bucket so that would be left if the bucket is going counter clockwise vertically. Are there any more forces on water inside the bucket at the top position and am I right about the direction of the two forces.
  2. jcsd
  3. Jan 6, 2009 #2
    Re: Water in the Bucket: Free Body Diagram?? (Vertical Centripetal Force)

    There are three forces I can think of off the top of my head. The question doesn't get to specific so it could be 2 or 3 forces and so on.

    Centripetal Force
    Tension Force in the rope

    The tension one is a most likely but there could not be one. I'll leave you to figure out the rest.
  4. Jan 7, 2009 #3
    Re: Water in the Bucket: Free Body Diagram?? (Vertical Centripetal Force)

    Yes you're right, there is gravity pulling vertically down, and there are contact forces with the bucket. But since the bucket feels centripetal force into the circle, the water will be overall pushed towards the centre of the circle by the walls of the bucket, hence the water feels a centripetal force.

    At the 'top' position then, both forces would be acting downwards.

    Hope that helps
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