math
posted by Confused .
A Ferris wheel 28.0m in diameter rotates once every 21.0s.
What is the ratio of a person's apparent weight to her real weight at the top?
What is the ratio of a person's apparent weight to her real weight at the bottom?

radius, r = 28/2 m =14 m
Period, T = 21 s
angular velocity, ω = 2π/21 rad/s
Centrifugal force, f= mrω²
actual weight, w = mg
apparent weight at top, wt = mg f
apparent weight at bottom, wb = mg+f
Solve for f and calculate wt/w and wb/w. 
so i have a question how do you solve for f if there is no m?

the m's cancel at some point in the equation