1. The problem statement, all variables and given/known data 2. Relevant equations 3. The attempt at a solution I know that the solution involves setting the normal force to zero and equating the radial component of gravity to centripetal force. But why is it not possible for the normal force to decrease at a sufficiently low rate such that even before the normal force reaches zero, the net force (normal+radial component of gravity) is insufficient for supplying the centripetal force, thus resulting in the boy falling off? Thanks for your time.