Hooke's law states that the elongation of a material is proportional to the applied stress within the elastic limits of the material.
Using Hooke's law
F = kx
570 = k * 0.9
k = 712.5 N/m
(a) energy at x = 0.8 m
U = 0.5 k x^2 = 0.5* 712.8* 0.8^2
U = 228 J
(b) U = 0.5 * 712.8* 0.09^2
U = 2.887 J
Elastic potential energy is the potential energy released as a result of the deformation of an elastic body. B. Spring extension is stored. This is equal to the work done to stretch the spring, which depends on the spring constant k and the stretched distance. The force exerted by the spring is the restoring force that helps return the spring to its equilibrium length.
