A 60 kilogram water skier is being pulled by a nylon (Young's modulus 3.7 x 109 N/m2) tow rope that is attached to a boat. The unscratched length of the rope is 11 meter and its cross-section area is 2.9 x 10-5 m2. As the skier moves, a resistive force (due to the water) of magnitude 180 Newton acts on her; this force is directed opposite to her motion. Find the change in length of the rope when the skier has an acceleration whose magnitude is 0.72 m/s2?