Question

when a car is going around a in a circular track with constant speed, what provides the centripetal firce necessary for circular motion

Answer 1

When a car moving around the circular track with a constant speed, there is a change in velocity and subsequently an acceleration. This acceleration is directed towards the center of the circle. And according to Newton's second law of motion, an object which experiences an acceleration must also be experiencing a net force. In such a motion speed remains the same but direction changes. The direction of the net force is in the same direction as the acceleration. So for an object moving in a circle, there must be an inward force acting upon it in order to cause its inward acceleration. This is called as the centripetal force. Keeping the car on a circle requires a friction force on the tires, called centripetal force, and it is directed inward towards the center of the circle.

Centripetal force is always directed towed the center of circle to bind the object in same track and avoid it from going out of the track.