Ok, here is a physics problem that I cannot figure out for the life of me. I feel as though I can't solve it without knowing either the mass of the bungee jumper or the spring constant for the cord. Is there a way to get it somehow? Perhaps an important number is missing? I would appreciate any and all help in trying to understand this problem. 1. The problem statement, all variables and given/known data A daredevil plans to bungee jump from a balloon 53.0 m above a carnival midway (Fig. P8.19). He will use a uniform elastic cord, tied to a harness around his body, to stop his fall at a point 10.0 m above the ground. Model his body as a particle and the cord as having negligible mass and obeying Hooke's force law. In a preliminary test, hanging at rest from a 5.00 m length of the cord, he finds that his body weight stretches it by 1.30 m. He will drop from rest at the point where the top end of a longer section of the cord is attached to the stationary balloon. (a) What length of cord should he use? (b) What maximum acceleration will he experience? 2. Relevant equations ka + ua = kb +ub f = -k*x w = f*d w = 1/2 *mv2^2 - 1/2 mv1^2 3. The attempt at a solution The first part was rather easy, I simply found the point of equilibrium between 10m and 53m, and PE was 0 at that point. The second part makes no sense to me. I do not know where to start to find maximum acceleration.