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Theory:

In the previous section, we have discussed several activities that we usually consider as work in day-to-day life.
 
For each of these activities, think of the following questions and try to answer them:
  1. What is the work being done on?
  2. What is happening to the object?
  3. Who (what) is doing the work?
Example 1 - Carrying a box
  
shutterstock_443607682.jpg
 
In most cases, carrying a box is not considered work. The force and distance you apply must be in the same direction for something to be recognised as work,  
 
In the case of carrying a box, you are using a vertical force to lift a box while you are moving horizontally in the distance. This indicates zero work is being done as the force and distance are not applied in the same direction.
 
Example 2 - A book falls off a table (free falls to the ground)
  
Falling_books_(33263680834).jpg
 
This is an example of work. There is a force (gravity) that acts on the book, which causes it to be displaced in a downward direction (i.e., "fall").
 
Example 3 - A man applies a force on a wall and gets exhausted
  
shutterstock_1170334213.jpg
 
This is not an example of work. The wall is not displaced. A force must cause a displacement 'for the work to be done'.
 
Example 4 -  A servant carries a plate full of meals above his head by one arm straight across the room at a uniform speed
 
pizza-41139_960_720.png
 
This is not an example of work. In this case, there is a force (the plate is pushed up by the servant) in upwards, and there is a displacement (the plate is moved horizontally across the room) in the horizontal direction. Yet, the force does not cause displacement. To cause a displacement, there must be a component of force in the direction of the displacement.
 
Example 5 -  A rocket accelerates through space
  
shutterstock_1918809284.jpg
 
This is an example of work. A force (the expelled gases push on the rocket) causes the rocket to be displaced through the space.
Reference:
https://pixabay.com/fr/vectors/pizza-serveur-italien-le-restaurant-41139/