Final answer:
Work is done when a force acts on an object and causes a displacement. The work done depends on the relative directions of the force and displacement.
Step-by-step explanation:
In physics, work is done on an object when a force acts on it and causes a displacement. Work is defined as the product of the component of the force in the direction of motion and the distance through which the force acts. If the force and displacement are in the same direction, the work done is positive. If they are in opposite directions, the work done is negative. If the force is perpendicular to the displacement, the work done is zero.