# Bungee jumping

**Classical Mechanics**Level 5

A bungee jumper jumps from a bridge with a \(3~\mbox{m}\) long bungee cord. Once the cord starts to stretch, it acts like an ideal spring with coefficient of elasticity \(k = 100~\mbox{N/m}\). What should be the minimum height of the bridge **in m** so that this jump is safe for the jumper?

**Details and assumptions**

- The jumper has a mass of \(80~\mbox{kg}\).
- The acceleration of gravity is \(-9.8~\mbox{m/s}^2\).
- There are at least two ways to solve this problem.
- Treat the jumper as a point mass at the end of the cord.