In: Physics
A thin uniform disk of radius r and mass m is spinning about its center at angular speed ω0. The disk is placed flat on a horizontal surface. The coefficient of kinetic friction between the disk and the surface is μ and constant for the entire area of contact. a) Find the frictional torque on the disk. (Hint: Divide the disk into many concentric rings.) b) How long will it take the disk to come to rest?