A roll of paper is rolled on the floor in such a way that it is leaving paper on the behind it as it rolls. The paper left behind remains stationary on the floor. The roll is given an initial velocity V= 7.5 m/s. The initial radius of the roll is R = 1 m. Find the velocity of the roll Vf in m/s, when the radius of the roll is r = 0.6 m. Assume the roll rolls without slipping and that gravity acts on the roll. Also assume that the mass distribution of the paper on the roll is homogeneous. (Take g = 10 m/s^2)