A passenger with mass 85 kg rides in a Ferris wheel like that in Example 5.24 (Section 5.4). The seats travel in a circle of radius 35 m. The Ferris wheel rotates at constant speed and makes one complete revolution every 25 s. Calculate the magnitude and direction of the net force exerted on the passenger by the seat when she is
(a) one-quarter revolution past her lowest point and
(b) one quarter revolution past her highest point