1. The problem statement, all variables and given/known data http://online.physics.uiuc.edu/cgi/courses/shell/common/showme.pl?courses/phys211/oldexams/exam3/sp08/fig23.gif [Broken] A child sends a hula hoop (moment of inertia I = MR^2) sliding without rolling across a smooth floor. The hoop has an initial velocity Vsliding. The hoop encounters a rough area where the (finite) coefficient of kinetic friction between the hoop and the floor is μK. After moving a few feet, the hoop is found to be rolling without slipping with a translational velocity Vrolling. Immediately after the hoop enters the rough area, it is both rotating and sliding. (True/False) 2. Relevant equations 3. The attempt at a solution I thought immediately after the hoop enters the rough area, it ONLY slides and then it rotates( I thought of it like this because there was a FRICTIONLESS surface before it goes into the frictional surface..) How can i distinguish either it 1)only rolls 2)only slides 3)slides with rolling... It's really confusing.. Please could someone help me out?