Answer
The rider experiences the most centripetal force at arch 4, then arches 1,2,3 are tie, and arch 5 has the least.
Work Step by Step
The equation to guide the thinking in this question is:
$F_{c}$=Mass$\times$($Velocity^{2}$/Radius)
Mass and velocity are held constant in this experiment. Radius is inversely related to centripetal force, so as radius increases centripetal force decreases. Arch 4 has the smallest radius(R), arches 1,2 and 3 all have the next greatest radius(2R), and arch 5 has the biggest radius of them all (3R).
