Two blocks, stacked one on top of the other, can move without friction on a horizontal surface, where M = 5.6 kg. The surface between the two blocks is rough, however, with a coefficient of static friction equal to 0.48.
(a) If a horizontal force F is applied to the 5.6-kg bottom block, what is the maximum value F can have before the 2.0-kg top block begins to slip?
(b) If the mass of the top block is increased, does the maximum value of F increase, decrease, or stay the same?