# Homework Help: Using energy concepts and possibly work bunjee jump problem

1. Mar 21, 2013

### SChiO

1. The problem statement, all variables and given/known data

Suppose you have a friend who wants to go bungee jumping for her birthday. She wants to jump off a high bridge over a river and be able to touch the water below right when she gets to the bottom of the bungee cord extension. You want to double-check all the physics of the bungee jump to make sure it is safe for her to go jumping.

2. Relevant equations

Identify a few things that you would like to know about the bungee jump. Then, making reasonable assumptions for some of the properties of this system, determine what needs to be true so that she has her birthday wish.

3. The attempt at a solution

I figured what I need to know is the height of the bridge, weight of my friend and the elasticity of the rope which I believe we can assume is similar to a spring. but I know my professor wants us to incorporate potential energy involving a spring and gravity but I'm not sure how to do so....

2. Mar 21, 2013

### Staff: Mentor

You have to know the gravitational acceleration of earth - the same setup will look differently if you perform the jump on the moon. The length of the rope (=the distance below the bridge where it starts to extend) will be relevant, too.

There are many ways to fix all parameters. Potential energy as parameter is an option, but not required.

3. Mar 21, 2013

### SChiO

Thanks that makes sense. Hopefully i get it right!