Question

given the following situations below, identify if work is being done or not and explain your answer.

1. A father pushing a grocery cart down the aisle of a grocery store.

2. a student lifting a backpack full of books upon her shoulder.

3. a frustrated person pushing again a wall due to his love life.​

Answer 1

Only in 3rd one work is not done, because on applying force there is no displacement of Wall. While in first and second options the work is done because there is visible displacement due to Force applied on the objects and angle between Force and displacement is not 90°.
NOTE: a student carrying a backpack will not have done any work as the angle between force and displacement is 90°(cos 90° =0).