a stock person at the local grocery store has a job consisting of the following five segments:
1) picking up boxes of tomatoes from the stockroom floor
2)accelerating to a comfortable speed.
3) Carring the boxes to the tomato display at constant speed.
4)decelerating to a stop.
5) lowering the boxes slowly to the floor.
During which of the five segments of the job does the stock person do positive work on the boxes?