A solid sphere of mass 0.750 kg and radius 5.00 cm is spun up to an angular velocity 10.0 rad/s, spinning clockwise. The sphere is held just barely above a flat platform of mass 5.00 kg, then released onto the platform. The sphere begins to skid and moves along the platform until it rolls without slipping. The coefficient of kinetic friction between the sphere and the platform is 0.70. The coefficient of friction between the platform and the ground is 0.05, and the platform begins to slide across the ground. Find an expression for the horizontal position of the center of mass of the sphere as a function of time (hint—it’s piecewise!), and note the times at which the sphere’s motion changes.