ANSWER and EXPLANATION
We want to know how to tell if work is done on an object.
Work is a result of a force acting on an object that thereby causes a displacement of the object. It is defined mathematically as:
[tex]W=F\cdot d[/tex]where F = force; d = displacement
Therefore, we say that work is done on an object when a force is applied to the object and it causes the object to move a certain distance.