E mal g es -1 53. A force F is applied to compress a spring P force constant 500 N m¹ and a spring Q, force constant 200 N m as shown in Diagram 30. The force increases from zero as x increases. Q F P (b) (c x = 18 cm x=0 cm x = 5 cm Diagram 30 Calculate the elastic potential energy when x = 10 cm. A 1.0 J C 2.8 J B 2.5 J D 3.4 J​