http://cache.rcdb.com/pictures/picmax/p5740.jpg I am doing an analysis on a roller coaster that is represented on the diagram attached. However, I am having trouble analysing the curve. The radius is 36.9m and it is 160km/hr going up and then it free falls back down from 115m for about three seconds. When I am going up do I just use a_centripetal = v^2/r to find the acceleration? When I am going down, I have to find the acceleration as well as the velocity, but how do I know where to start?