Question

In these figures, we see a boy named Billy riding a carnival ride called the Rotor and the free-body diagram for the forces acting on him. What must be the magnitudes of the vectors (f)wall,Billy and (W)Earth,Billy if Billy remains at the same height along the wall?

1) The magnitudes of (f)wall,Billy and (W) Earth,Billy are equal.

2) (N)wall,Billy and (f)wall,Billy must be equal in magnitude.

3) (f) wall,Billy is greater than W Earth,Billy to keep Billy from falling.

4) (f)wall,Billy depends on the magnitude of (N)wall,Billy , but the magnitude of (W)Earth,Billy is always the same.

Answer 1

There are two forces the wall is creating: an inward force, which is equal to centripetal force (actually, it is the centripetal force). The other force is the force of friction, upward, which equals Billy's weight (if he is not slipping).

I do not know which are labeled as such in your diagram, nor the "Earth" force.

Answer 2

heh