1. The problem statement, all variables and given/known data When the train has passed at the point C, the radii of curvature is 20 m and the apparent weight is 2 2 times bigger than the real weight. At the moment when the picture was taken, the train was at the point s, located 8 m higher than the hollow C. At s, the radii of curvature est 16m. Calculate the quotient between the apparent weight at the point S and the real weight. There is no friction and no air resistance. http://imgur.com/R2A4pya 2. Relevant equations Sum of force in y = (mv^2)/radii Energy at s = energy s k=mv^2/2 U=m*g*y 3. The attempt at a solution I know what to do : I calculate the speed at the point C. I get 62,6 m/s I put up equations which respect that Es=Ec to find my speed at S I do the sum of forces at S and find n and divide it by mg. Now, the only point which Im not sure is what is the height the point S ? I is 48 m ?