Answer:
The net centripetal force acting on object B is one-ninth of the force acting on object A.
Step-by-step explanation:
The centripetal force acting on an object when movieng in circular paath is given by :

Here,
m is the mass of the object
r is the radisu of circular path
is angular velocity
Here, two identical objects (A, B) travel circles of the same radius but object A completes three times as many rotations as object B in the same time.
It is clear that, centripetal force is directly proportional to the square of agular velocity. New centripetal force becomes :

So, the net centripetal force acting on object B is one-ninth of the force acting on object A.