Part A
Bungee cords designed to U.S. Military specifications (DoD standard MIL-C-5651D, available at http://dodssp.daps.dla.mil) are characterized by a force constant in the range of about 10-20 N/m. Suppose that you are designing a bungee jump off of a bridge that is 30.0 m above the surface of a river running below. To get an idea for the maximum cord length, calculate the unstretched length of cord with a spring constant of 10.0 N/m that will result in an 85.0 kg jumper who leaves the bridge from rest ending their jump 2.0 m above the water's surface. (The 2.00 m builds in a safety margin for the height of the jumper, so you can neglect the height in your calculation.)