The margin ever here is low. When most people want to do a bungee jump to not do this, because if it just turns out that he had extended about two meters more than he expected to, he would have at least hit the plank. So maybe it's not a catastrophe, but it was a risky thing to do. And so you would think it would just your acceleration would be equal to g 9.8 meters per second squared. But there is an interaction with the cord. It is transfer and momentum from the cord to you. The net effect is that you accelerate faster than gravity, because the cord is actually pulling you down.