Asmall mass m starts from rest and slides from the top of a fixed sphere of radius r. a. if the sphere is frictionless, at what angle theta from the vertical does the mass leave the surface? b. suppose there is friction between the mass and the sphere with friction coefficient meu_s =0.1. what is the minimum angle theta_min at which the mass will start to slide along the sphere? c. the mass is now placed just past this minimum angle and released. the coefficient of kinetic friction meu k is small but not zero. does the mass fly off at a larger or a smaller theta than found in part (a)? assume theta is defined with respect to the top of the sphere.