The force you apply to each section is the same you apply to the whole spring, but the extension of each section is dX/N (if dX is the extension of the entire spring)
GPE= 70.56 J -------------------> GPE= mgh-------------> X= height 70.56 = 6(kg) * 9.8(m/s/s) * X 70.56 = 58.8X 70.56/58.8= 58.8X/58.8 X= 1.2 The height is 1.2 feet or meters (whatever unit you are using in this problem)
