|Is it possible to greatly increase the speed of a roller coaster, while retaining some safety, by applying the same theory that is used in Bullet Trains? — JA, Henderson, NV
While roller coasters could be made faster if they used the high performance tracks of bullet trains, smoothing out the tracks would only make the ride less jittery and wouldn't reduce the accelerations needed to complete the turns. The faster the train moves, the faster everything must accelerate as the track bends. Doubling the speed of the roller coaster would double the changes in velocity associated with each bend and would halve the time available to complete that change in velocity. As a result, doubling the roller coaster's speed would quadruple the accelerations it experiences on the same track and thus will quadruple the forces involved during the ride. A roller coaster ride already involves some pretty intense forces and accelerations. If those forces and accelerations were increased by a factor of 4, they would be more than most people could handle. Thus I wouldn't expect many riders on a double-speed bullet train roller coaster.