You want to design a curve, with a radius of curvature of 35.0 m, so that a car can turn at a velocity of 15 m/s on it without depending on friction. At what angle must the road be banked?

1 answer

No tire friction is required if the force on tires at the road surface, Fn, is normal to the surface. That requires
Fn sinA = M*V^2/R (to provide the centripetal force), and
Fn cosA = M*g
(to balance the weight).
A is the banking angle.
This leads to
tanA = V^2/(R*g)