Here's why:
* Work is defined as the force applied multiplied by the distance moved in the direction of the force.
* Formula: Work (W) = Force (F) x Displacement (d)
* In this case, d = 0, so W = 5 Newtons x 0 = 0 Joules
Example: Imagine pushing against a wall. You exert force, but the wall doesn't move. Since there is no displacement, no work is done.