Reverse the direction of the load in Example 2.4 and recalculate the total potential energy. Then use this value to obtain the equilibrium value of displacement.
Example 2.4
For the linear-elastic spring subjected to a force of 1000 lb shown in Figure 2-20, evaluate the potential energy for various displacement values and show that the minimum potential energy also corresponds to the equilibrium position of the spring.
Figure 2-20

F = 1000 lb k = 500 lb/in.