An amusement park ride consists of a rotating vertical cylinder with rough walls. The floor is initially about halfway up the cylinder wall as shown. After the rider has entered and the cylinder is rotating sufficiently fast, the floor is dropped down, yet the rider does not slide down. The rider has a mass of 80 kilograms, the radius of the cylinder is 3.2 meters, the angular velocity of the cylinder when rotating is 2.5 radians per second.

(a) Calculate the normal force applied to the rider.

(b) Calculate the frictional force applied to the rider.

(c) What is the minimum value the coefficient of static friction can have if the rider does not slide down?