Why do we say "work done" and "energy change"

Answer with Explanation:

We say "work done" because it is the amount of force that causes an object's movement or displacement. Without movement or displacement, there is "no work done." So, it has to happen first or you have to push or pull something first in order to say that work has been done.

We say "energy change" because one form of energy is being transformed into another form of energy. For example, chemical energy can be transformed or changed into light energy through the combustion of coal. Energy can never be destroyed nor created and this follows the "Law of Conservation of Energy."