At an amusement park there is a ride in which cylindrically shaped chambers spin around a central axis. People sit in seats facing the axis, their backs against the outer wall. At one instant the outer wall moves at a speed of 3.30 m/s, and an 80.3-kg person feels a 517-N force pressing against his back. What is the radius of a chmber?

Force towards centre = mv^2/r

Force = 517, m = 80.3, v = 3.30

Substitute values and find r, radius!