Given:
F_gravity = 10 N
F_tension = 25 N
Let's find the net centripetal force exterted on the ball.
Apply the formula:

From the given figure, the force acting towards the circular path will be positive, while the force which points directly away from the center is negative.
Hence, the tensional force is positive while the gravitational force is negative.
Thus, we have:

Therefore, the net centripetal force exterted on the ball is 15 N.
ANSWER:
15 N
From an energy balance, we can use this formula to solve for the angular speed of the chimney
ω^2 = 3g / h sin θ
Substituting the given values:
ω^2 = 3 (9.81) / 53.2 sin 34.1
ω^2 = 0.987 /s
The formula for radial acceleration is:
a = rω^2
So,
a = 53.2 (0.987) = 52.494 /s^2
The linear velocity is:
v^2 = ar
v^2 = 52.949 (53.2) = 2816.887
The tangential acceleration is:
a = r v^2
a = 53.2 (2816.887)
a = 149858.378 m/s^2
If the tangential acceleration is equal to g:
g = r^2 3g / sin θ
Solving for θ
θ = 67°