Work
Tanusri Gururaj, Academic content writer of Physics at Edumarz
To understand the scientific definition of work, let us take a few examples:
A person reads a book and writes notes.
Work not done.
A person pushes a heavy box but it does not move.
Work not done.
A person pushes a heavy box and it gets displaced.
Work is done.
A person lifts a book.
Work is done.
The above examples show that for work to be done, two conditions are necessary:
Force
Displacement
Work is defined as the product of force acting on a body and displacement.
W = F x s
Where W is the work done
F is the force acting on the object
s is the displacement of the object
SI unit of work = N m or Joule (J)
1 Joule (J) can be defined as the amount of work done when a force of 1 newton (N) displaces the body by 1 metre (m) along the line of action of force.
Work is positive when the displacement is in the direction of force and negative when displacement and force are in opposite directions.