Two boxes of masses 3 kg and 5 kg are placed at the floor of an elevator as shown in the figure. The 3kg box is on the top of the 5 kg box. If the elevator is descending from rest with a constant acceleration. In one second, the elevator has descended a distance of 0.5m.

        a.    (5 points)
        What is the elevator's acceleration?

 

b.    (5 points)
Draw free body diagrams for the two boxes, showing all forces acting on each of the boxes.