Q: When a car is rounding a banked curve (the surface of the road is angled), what type of friction is there between the car and the road that helps create the Fc and what direction is the friction pointing? I am slightly confused. As I know the car is moving, so wouldn’t the friction be kinetic?
A: Refer to the picture! Car moves in the Tangential direction (x-axis) while the Friction force can only have components in Radial and Vertical directions (no motion in these two directions). Therefore, the friction is static friction. In addition, the normal force and the friction could contribute to the Centripetal force, but the weight doesn’t. Depending on the linear speed, the static friction could be pointing away from the center of circle, to the center of circle, or zero!
