Question

A heavy pulley is used to descend a height without landing at a great speed. Let the pulley be a uniform disk of mass "M" and radius "R". The descent has a height "h" and you want the landing speed to be "v". You design the pulley to not have enough inertia to slow down a person enough. This lets you adjust the inertia of the pulley by adding masses at the edge of the pulley. A person releases from rest and lands at the bottom. What is the amount of mass that must be added in order to produce a certain landing speed? What is the value for the added mass if the person is 80 kg, the pulley is 100 kg, the height to be descended is 5 meters, and the landing speed is to be 2 m/s?

Answer 1