A frightened 15.5 kg box is pushed into a spring, which happens to have a k of 1, 164 N/m. This spring will shoot the box across a frictionless surface with a 2.0 long rough patch in the middle with an unknown u.k. A second, spring is at the other end just to bounce the box back so it travels back and compresses the first spring. If the first spring is compressed 35 cm at the start and is compressed 27 cm at the end of the boxes travel, what is the u.k of the rough patch