How does the work done depend on the magnitude of the pulling force?

The work done ($$A = F \cdot s$$) is directly proportional to the pulling force ($$F$$) if the distance ($$s$$) remains constant. In this experiment, however, the distance is kept constant, but the force increases with the number of weights. Thus, as the pulling force increases (due to more weights), the work done also increases, provided the distance is the same.