Thread: Frictional force, centripetal force and centrifugal force.

I have currently learned in physics that car doesn't skid while rotating in circular path because frictional force act towards centre to provide balance.If a velocity of car is increased such that frictional force is not sufficient to maintain balance,the car will skid radially outward.This radially outward force=centrifugal force.But, I have daught how can centrifugal force become greater than frictional force because fs=centripetal force=centrifugal force?

What you are dealing with here is the difference between static and kinetic friction. static friction is the friction between two surfaces when they are not moving with respect to each other. (like between the tire and road when the tire is not skidding). There is a maximum force the static friction can provide. With the tire, up until the centrifugal force exceeds this maximum force, static friction can counter the centrifugal force and keep the tire from skidding. Once centrifugal force gets large enough, it becomes more than what static friction can counter and the tire begins to skid. Now, kinetic friction takes over, which is the friction between two surfaces sliding against it each other. Kinetic friction for two surfaces will be less than the static friction for the same surfaces. Thus once the tire starts to skid, the friction that can be provided by the road to the tire drops and the car actually skids easier.

So to put it simply. there is a maximum centripetal force that friction between the tire and road can provide, and once centrifugal force exceeds this, the car skids.

Since centripetal force=centrifugal force then how can centrifugal force become large?

Originally Posted by sagarkaran

Since centripetal force=centrifugal force then how can centrifugal force become large?

You are correct, but the friction of the wheels on the road has to be able to provide sufficient force to maintain the centripetal acceleration to keep the vehicle moving in the circular path. If it cannot provide this force, then the vehicle continues in a straight line tangent to the circular path it was following before it started to skid. The force needed to keep it moving in a circular path increases with the speed.

Then,Is it right to say that car will skid tangentialy(not radially outward )if frictional force get lost?