You go bungee jumping from a bridge that is 100m above a river, the bungee cord has an unstretched length of 50m and a spring constant of k=700 N/m You have a mass of 45kg. 1. How fast are you falling when you just start to stretch the cord and how long does it take to reach this point? 2. What types of mechanical energy does the system (you and the bungee cord) have just before you jump. What types of energy does the system have at the instant you come to rest at your lowest point? 3. What is your height above the river at your lowest point. 4. What would be the period of your oscillation if it is assumed that the bungee cord acts like a perfect spring. whew, thats alot. Ok so for 1 it is asking for velocity and time, but I have no idea on where to start or what equation to use For 2, just before you jump you dont have any kinetic energy but you do have gravitational PE and elastic PE correct? Am I missing any? When you come to rest at the lowest point, once again no KE, but elastic PE? For 3, I know that enrgy stored in the bungee cord is 1/2 k (x)^2 where x is the amount of stretch, but how do I get height from this? And for 4, T = 2pi square root of (m/k) is that it? Please help!!!