A block of mass M is suspended from two identical springs of negligible mass, spring constant kand unstretched length L. First, one spring is attached to the end of the other spring. The block is then attached to the end of the second spring and slowly lowered to its equilibrium position. The two springs stretch a total distance of X1 , as shown in Figure 1 above. Next, the springs are hung side by side. The block is attached to the end of the springs and again slowly lowered to its equilibrium position. The springs each stretch a distance of X2 , as shown in Figure 2 above. Which of the following equations correctly shows the relationship between X1 and X2 ?