Mark weighs 600 N and is hanging from a bungee cord which is stretched a distance of 3 m how much would the same bungee cord stretch under the load of Chris who weighs 900 N?

4.5 metres

Explanation:

Using Hooke's Law ()

We need to find the spring constant of the bungee cord with the given extension and force, we can do this by substituting in known values.

Now we have found the spring constant of the bungee cord, we can substitute it in for the a different force. As the cord is the same we can use the same spring constant.