An ideal spring of negligible mass is 13.00 cm long when nothing is attached to it. when you hang a 3.00-kg weight from it, you measure its length to be 14.50 cm . if you wanted to store 10.0 j of potential energy in this spring, what would be its total length? assume that it continues to obey hooke's law. express your answer numerically. if there is more than one answer, enter each answer, separated by a comma.