Rotation 3

(c)...noting that impulsive torque due to fixed forces is negligible then writing the conservation of energy about the lline at height h=r/4.....we get

also note that since there will be no slipping hence that point will act as axis of rotation at that istant

initial angular momemtum= mv₀(3r/4 )+ I_cv₀/r
final angular momentum=(3/2)mr²(v^|/r)

equate and solve for v^|