To solve this problem we will make a graph that allows us to understand the components acting on the body. In this way we will have the centripetal Force and the Force by gravity generating a total component. If we take both forces and get the trigonometric ratio of the tangent we would have the angle is,
[tex]T_x = nsinA = \frac{mv^2}{r}[/tex]
[tex]T_y = ncosA = mg[/tex]
Dividing both.
[tex]tan A = \frac{v^2}{rg}[/tex]
[tex]tan A = \frac{11.7^2}{50*9.8}[/tex]
[tex]A = tan^{-1} (0.279367)[/tex]
[tex]A = 15.608\°[/tex]
Therefore the angle that should the curve be banked is 15.608°