Explanation:
[tex]centripetal \: force = \frac{m {v}^{2} }{r} [/tex]
Centripetal force = 45 * 2 = 90 N
Therefore, centripetal force acting on a 45 kg boy riding in one of the cars when the car is on the top of the ferris wheel is 90 N.
The force exerted by the seat on the boy when the car is at the top of the ferris wheel is a centrifugal (pseudo force) acting (since the since the seat is in non- inertial frame) in exact opposite direction (Outwards) as the centripetal force and is equal in magnitude.