1. The problem statement, all variables and given/known data The diagram show a student before and after she makes a bungee jump from a high bridge above a river. One end of the bungee cord, which is of unstretched length 25 m, is fixed to the top of a railing on the bridge. The other end of the cord is attached to the waist of the student, whose mass is 58 kg. After she jumps, the bungee cord goes into tension at point P. She comes to rest momentarily at point R and then oscillates about point Q, which is a distance d below P. 2. Relevant equations The bungee cord behaves like a spring of spring constant 54Nm–1. Calculate the distance d, from P to Q, assuming the cord obeys Hooke’s law. 3. The attempt at a solution What I can’t see is why this works for this distance when the cord stretches from P all the way down to R. Also only at P is the force just due to the weight (mg). I am assuming it has something to do with Q being the equilibrium position of the oscillation. Any pointers for my thought processes gratefully received.