When a force F is applied on an object, in a direction parallel to the displacement d of the object, then the work W done by the force can be calculated as:
Replace F=315N and d=2.04 to find the total amount of work done in the process:
Therefore, the amount of work done by the person while pushing the box over a distance of 2.04 with a force of 315N, is 642.6 Joules.