A uniform cube of mass M rests tilted against a vertical wall at an angle 0, as shown in the figure below. There is no friction between the wall and the cube, but the coefficient of static friction us between the cube and the floor (at the point P) is large enough to keep the cube from slipping. M N21 8 (a) (3 pt) By considering the total torque about the point P, explain why o must be less than 45 degrees for the cube to rest against the wall. (Hint: Think about the center of mass of the cube.) (b) (4 pt) Find an expression for the normal forces M and N2 shown in the figure, in terms of M, g, and the force of friction f. (c) (3 pt) Express the frictional force f in terms of M, g, and 0. (Hint: When you compute any torques, you can define the length of the side of the cube to be L, even though this will cancel in your final answer. )