Radial acceleration: Rotating Carousel

[paxian]

Homework Statement

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.

Homework Equations

net force = ma= mv^2/r
weight = mg

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?

 

[MrNerd]

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.

 

[paxian]

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.

Thank you!