The problem is as follows: "Bungee Barbara jumps off a crane platform 30m above the ground. The bungee cord to which she is hooked has an unstretched length of 9.0m We assume the bungee cord behaves like an ideal spring with spring constant k=100 N/m. Barbara has a weight of 600 N. At what height will the net force acting on Barbara be zero?" I don't understand why this point is not the lowest point in the fall. I mean, wouldn't the net force be zero when the force of gravity and the tension in the spring are balanced, and wouldn't that be when Barbara momentarily comes to rest at the lowest point?