Hooke's law describes a certain light spring of unstretched length 33.0 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 42.0 cm.
(a) Find its spring constant. 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 185 N. Find the length of the spring in this situation.