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Homework Help: Radial acceleration: Rotating Carousel

  1. Oct 7, 2011 #1
    1. The problem statement, all variables and given/known data
    A horse located 8.0m from the central axis of a rotating carousel moves at a speed of 6.0 m/s. The horse is at a fixed height (it does not move up or down). What is the net force acting on a child seated on this horse? The child weight is 130N.


    2. Relevant equations
    net force = ma= mv^2/r
    weight = mg

    3. The attempt at a solution
    m = 130N/(9.8m/s^2)=13.3kg
    net force = 13.3kg *(6m/s)^2/8.0m = 59.9N

    I think the answer 59.9N seems reasonable... However, I am wondering if I need to do anything with the gravitation force - Weight and the normal force
    like: netforce= N - W= ma
    N=W+ma????
     
  2. jcsd
  3. Oct 7, 2011 #2
    If the horse does not move up or down, then it has a net force of 0. This means that the gravitational and normal force cancel each other out. As a result, the only net force acting on the child is the centripetal force you found, the 59.9N.
     
  4. Oct 7, 2011 #3
    Thank you!
     
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