Answer:
F = 0 [N]
Step-by-step explanation:
To solve this problem we must perform a summation of forces in the direction of the vertical axis. Where the positive force is that of the tension of the upward force, while the force exerted by the weight is directed downward with a negative sign.
ΣF = 0
15 - 15 + F = 0
F = 0 [N]