A mechanical buffer assembly consists of two identical parallel springs, each with a spring constant k=250 N/mk = 250\text{ N/m}k=250 N/m, as shown in the diagram.
A force F F\,F is applied to stretch the assembly by a distance x=12.0 cmx = 12.0\text{ cm}x=12.0 cm.
Calculate the total elastic potential energy stored in the two springs.
0.90 J0.90\text{ J}0.90 J
1.8 J1.8\text{ J}1.8 J
3.6 J3.6\text{ J}3.6 J
7.2 J7.2\text{ J}7.2 J