Solving a problem in physics section 48 point 66 mechan

66. known circus attraction: the inner surface of a vertical cylinder at high speed riding motorcycle, describing a horizontal circle. Cylinder radius R = 13 m, the center of mass of the motorcycle with a man separated from the place of contact with the tire wall at a distance r = 0,80 m, the coefficient of friction of tires on the wall of μ = 0,60. Determine minimum speed υmin, in which no dumping, the rider can move.