sorry Idk the answer ..???
A because the girl in that instant is not moving up or down so
( up forces)=(down forces )
The up forces is the tension of the rope and down forces us mg -the gravitational force on the girl by the earth
Answer: ma is the formula of Newton's Second Law of Motion. Newton's Second Law of Motion is defined as Force is equal to the rate of change of momentum. For a constant mass, force equals mass times acceleration.
Explanation: Newton's second law of motion is F = ma, or force is equal to mass times acceleration.
To solve this problem we will apply the concepts related to the balance of Forces, the centripetal Force and Newton's second law.
I will also attach a free body diagram that allows a better understanding of the problem.
For there to be a balance between weight and normal strength, these two must be equivalent to the centripetal Force, therefore


Here,
m = Net mass
= Angular velocity
r = Radius
W = Weight
N = Normal Force

The net mass is equivalent to

Then,

Replacing we have then,

Solving to find the angular velocity we have,

Therefore the angular velocity is 0.309rad/s
Explanation:
Below is an attachment containing the solution.