a Math textbook weighing 1.4 kg and a Physics textbook weighing 2.2 kg are stacked on top of each other on a table. A horizontal force of 6.7 N is applied to the bottom book. Friction between the two books is 0.88N. Kinetic friction between the bottom book and the table top is 1.3 N. a) What is the normal force acting on both books by the table top? b) What is the net force in the horizontal direction? c) What is the acceleration of the stack of books