The tractor has a weight of 8000 lb with center of gravity at G. Determine the greatest...

The tractor has a weight of 8000 lb with center of gravity at G. Determine the greatest weight of the log that can be pushed up the incline. The coefficient of static friction between the log and the ground is μ_s = 0.5, and between the rear wheels of the tractor and the ground μ’_s = 0.7. The front wheels are free to roll. Assume the engine can develop enough torque to cause the rear wheels to slip.