The Wall of Death in an amusement park is comprised of a vertical cylinder that can spin around the vertical axis. Riders stand against the wall of the spinning cylinder and the floor falls away leaving the riders held up by friction. The radius of the cylinder is 3.95 m and the coefficent of static friction between the rider and the wall is 0.350. Find the tangential velocity of the spinning wall necessary so that the riders do not slip down the wall.