Answer:

Step-by-step explanation:
The radius of curvature of the velodrome, r = 20 m
Speed of cyclists, v = 15.5 m/s
Let
is the angle at which the surface should be banked. The horizontal and vertical forces acting on the cyclists are as follows :


From the above two equations,




So, the angle at which the surface is banked is 50.79 degrees. Hence, this is the required solution.