1. The problem statement, all variables and given/known data The natural length of the bungee cord is 10m Sam stops falling and first comes to rest momentarily when the length of the bungee cord is 18metres. Height of the tower was calculated to be 19.6metres What is the spring constant of the bungee cord? 2. Relevant equations mgh 0.5kx^2 3. The attempt at a solution after free falling 10metres the gravitational potential would be 70*10*9.6=6720. then equate that to 0.5kx^2, so 6720=0.5k*8^2, thus k=210N/m. I was absolutely confident my solution was correct but turns out it isnt.