A 12.0-kg box is pushed along a horizontal surface by a 24-N force as illustrated in the diagram. The 12-kg box eventually comes into contact with a 4.0-kg box made of the same material. The coefficient of kinetic friction between each box and the surface is 0.080. 4.0 kg 12.0 kg 40 Fapp = 24 N a. What is the acceleration of the 12-kg box? Include a FBD of the 12-kg box. (3 POINTS) b. What is the acceleration of both boxes when they are moving together with the same applied force? (2 POINTS) c. What force does the 4.0-kg object exert on the 12.0-kg object when the two are moving together? (2 POINTS)