Centripetal force question (1 Viewer)

[Everwinter]

The diagram below is a roller coaster track, the person riding the rollercoaster is feeling their weight increase and decrease at different points. Which point, A or B is the apparent weight of the rider at the greatest?




I choose B but the answer choose A, the reason for the A in the answer is that A is at a lower point, thus it has a higher velocity and centripetal force. However my issue is that according to the equation F = mv^2 / r, the centripetal force would be greater when the radius is smaller, in other words, point B that has a smaller radius would have a higher centripetal force and the apparent weight. Is there an error in my logic, or is the answer wrong? (apparent weight is the normal force acting against the rider)

 

[Vaibhav123456]

Due the larger difference in height from the starting point and the conservation of energy, the KE (and the velocity) will be higher at A (since change in GPE = change in KE). The radius is only for the arc of the circle at the troughs which I guess in this case is assumed to be the same, hence the centripetal force is larger at A. This results in a larger normal force and a higher apparent weight.

 

[Everwinter]

Thanks