If a curve with a radius of 94.5 m is perfectly banked for a car traveling 72.4 km/h, what must be the coefficient of static friction for a car not to skid when traveling at 96.4 km/h?

Answer 1

First compute the "perfect bank" angle at the 72.4 km/h speed.

Then require that the centripetal force at the higher speed be provided by the maximum friction force compatible with the static friction coefficient.