Banked Curves and Static Frictional Components

[Starwing123]

The part of the tire on the ground of a moving car is relatively stationary compared to the ground, right? The way the wheels work is the friction parallel to the direction of movement right? So when we calculate centripetal acceleration for cars going in a circle and the friction forces, why do we not have two components of friction?

 

[ehild]

The part of the tire on the ground of a moving car is relatively stationary compared to the ground, right? The way the wheels work is the friction parallel to the direction of movement right? So when we calculate centripetal acceleration for cars going in a circle and the friction forces, why do we not have two components of friction?

The blue sentence is not true. When the car travels along a circle, the friction can act against slipping both in tangential direction, along the circle, and also up or down along the slope, although the tangential component of static friction is zero when the car moves with uniform speed.

ehild

 

[Starwing123]

Oh, Thanks! I didn't realize that the tangential friction is 0 b/c the car is moving at a constant speed.