A large, cylindrical roll of paper of initial radiusR lies on a long, horizontal surface. The outside end of thepaper is nailed to the surface. The roll is given a verylight push (initial speed close to zero) and commences tounroll. Assume the roll has a uniform density & thatmechanical energy is conserved in the process. What is the speed of the center of mass of the roll when its radius hasdiminished to r?