It is your birthday, and to celebrate you are going to make your first bungee jump. You stand on the bridge 110 m above a raging river and join a 31-{\rm m}-long bungee cord to your harness. A bungee cord, for practical purposes, is just a long spring, and this cord consists of a spring constant of 43 N/m. Suppose that your mass is 71 kg. After a long hesitation, you dive off the bridge.
Explain how far are you above the water if the cord reaches the utmost elongation?