Physics! Urgent! Urgent!?

A student of weight 656 N rides a steadily rotating Ferris wheel (the student sits upright). At the highest point, the magnitude of the normal force F->N on the student from the seat is 583 N. (a) What is the magnitude of F->N at the lowest point? If the wheel's speed is doubled, what is the magnitude F_N at the (b) highest and (c) lowest point?