You and a few friends decide to go bungee jumping off a bridge above a river. The unstretched length of bungee cord (without any weight put on it) is 11.0 m. On the bridge, one end of the cord is connected to the jumper, and the other end to a crane whose height above the bridge can be adjusted.

Initially, the crane adjusted the height of one end of the bungee cord with a mass of 10.0 kg resting on the bridge attached to the other end. You noted that the crane hoisted the other end of the bungee cord so that the mass is just hanging at the equilibrium point. The stretched cord measured 20 m. 

It is your turn to jump.  You weigh 80.0 kg. The end of the bungee cord is attached to you on the bridge (that is, the cord is already stretched at 20 m when you are on the bridge). Before you jump, you want to calculate:

Part a) The new equilibrium position measured from the bridge where you will eventually end up.

Part b) The period of oscillation.

Part c) The lowest point you will reach below the bridge.

Part d) The time elapsed for you to reach the lowest point for the first time.