A uniform sphere of mass M and radius r rolls without slipping inside a track with the cross-section of a semicircle of radius R (R > r). The sphere's motion is confined to a vertical plane. In the figure below, point B becomes point C when the sphere is at the angular position θ = 0. Let θ be the angular displacement of the sphere about its center.
a) Write down constraints for the sphere's motion.
b) Derive the equations of motion from the Lagrangian.
c) Determine and interpret the constraint forces.
d) Determine the period of oscillations of the sphere about the equilibrium position (θ = 0 is the equilibrium position), assuming small angular displacements.
e) Determine the period of oscillations of the sphere about the equilibrium position if no force of friction exists between the sphere and the track.