Question

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) carrying 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?

Answer 1

Answer:

option 1 and option 2

Explanation:

option 1 and option 2

1)Take up the box: force is upwards, displacement is upwards as well, so good work as force & displacement are in the same direction

2) Accelerating:: because the individual is moving, force is positive, displacement is also in the same direction, so the work is positive.

3) carrying box at fixed speed :: as speed remain constant , force = 0 , therefore work =0

4) Decelerating to stop :: force is -ve because it is moving to finally stop, thus negative work

5) Lowering of the box :: force acts up direction , displacement is down , hence -ve work