In an amusement park one of the machines consists of a large vertical cylinder that rotates around an axis fast enough that a person inside is held against the wall as shown in the figure. The coefficient of friction between the wall and the person is us, and the radius of the cylinder is R. (a) Show that the maximum period of revolution needed to prevent the person from falling is T = (4m Rus/g) 1/2. (b) Obtain a numerical value for T if R = 4.00 m and us = 0.400. How many revolutions per minute does the cylinder complete