Diver in Distress: Velocity of a Wave Traveling Through a Cord

Summary: This Learning Object is a Word document where a long-answer problem is solved. The problem involves a diver who is about to be attacked by a shark and wants help from her crewmates. How long will it take for her shaking oxygen cord to be noticed by her crew?
http://www.slideshare.net/igormihajlovic3975/physics-learning-object-3-44397523