Answer:
151.2 N
Explanation:
The upward force at A is 135/(135+325) times the total weight of the generator. The CW torque about point O that produces is ...
(460 mm)(135/460)(160 kg)(9.8 m/s^2) = 211.68 N·m
For F to produce half that torque, it must be ...
F(0.7 m) = (211.68 N·m)/2
F = 211.68 N·m/(1.4 m) = 151.2 N