The bottom 1-kg-mass in the figure, has the ability to make a variable incline of angle θ, for the top equally massive object to reside on. The bottom mass is on a frictionless surface, while the coefficient of static friction between the two masses is 2/3. A force F, can be applied in the horizontal direction, as shown in the figure, on the bottom mass. (a) If the force F, is zero, what is the maximum angle the incline can be without the top mass slipping? (b) If the angle θ is reduced to zero, what is the max force F, that can be applied to the bottom mass without the top mass slipping? (c) The incline is now set to an angle of 16.845º, what is the maximum force F that can be applied to the bottom mass and still not have the top mass slip?