Centripital Force

[kfcman289]

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When a car is driving around in a circle, is it static friction or kinetic friction that supplies the force and why?

 

[cheylandis]

Static friction is the force that acts on the tire. Although it is rolling, the point at which the tire meets the asphalt is stationary for the moment it is in contact.

The friction force would become kinetic if the tire lost traction and began to slide.

 

[kfcman289]

Why would sliding cause kinetic friction to now take place?

 

[jxpham]

Why would sliding cause kinetic friction to now take place?

Static friction=Think about two objects, one on top of another, not sliding at all, thus, when a tire rotates but not slide, then the point of the contact of the tire on the road is not sliding, so each instantaneous point of contact is "static"/non-moving to the road.

Kinetic friction=Same two objects, but now they are sliding. That means when you car is sliding, your tire is rotating but sliding at the same time.

Another note, u(kinetic) is less than u(static) that is why when you are beginning to slide, you want to counter steer to prevent sliding so that your car has more "gripping" power.