Question #7954d

2 Answers
Jul 20, 2016

Work is one of the many form of energy.


Work measure the quantity of kinetic energy that a force #F# requires to move a body for a distance #s#.
So the work is measured in Joule like any other energy. On the other hand, energy can be more general. For example the potential energy of a body on a tower is the energy that can be transformed in work (of the free fall) once the body is released.

Jul 20, 2016

I see work as energy in movement giving, as end result, a transformation of its form inside a system.


As an example I think of a certain amount of energy in a system, say #100J#.
The system will be a person, a box and a cupboard;
Now, I consider our specific #100J# as "Chemical" Energy (kind of potential energy stored in the fats/sugars of our body). Our body operates on the box, basically, extracting this energy and allowing it to emerge and to be changed, through a physical process, into another form, Potential Energy (gravitational).
This “new” energy form is now stored away into the new configuration (spatial) of our system (The box is up there!).

Finally the box can fall from the cupboard and in this other physical process energy is changed from Potential Energy into Kinetic Energy (energy is extracted from the system as work and changed).

In these two processes (lifting and falling) the extraction of energy was made through work that, in a simplistic way, could be seen as energy that exits from a configuration to change into another.
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...Probably I confused you even more...