Work of 1 Joule is done in stretching a spring from its natural length to 16 cm beyond its natural length. What is the force (in Newtons) that holds the spring stretched at the same distance (16 cm)? Hooke's law and Work Done in Stretching a Spring The Hooke's law states that the force F applied is proportional to the displacement of spring during its compression or expansion. Mathematically, it is denoted as F = kx, where k is the spring constant. 2 The work done by a continuous force when the object is displaced from to is given by W = F. dx