Hooke's law describes a certain light spring of unstretched length 33.6 cm. When one end is attached to the top of a doorframe and a 7.31 kg object is hung from the other end, the length of the spring is 42.4 cm. (a) Find its spring constant.kN/m (b) The load and the spring are taken down. Two people pull in opposite directions on the ends of the spring, each with a force of 191 N. Find the length of the spring in this situation.