How does friction affect the motion of objects?

Friction is a force that acts between surfaces in contact and opposes the relative motion of those surfaces. When an object is in motion, friction works against that motion, which can cause the object to slow down or eventually come to a stop. For example, if you slide a book across a table, the friction between the book and the table opposes the sliding motion, thereby reducing the speed of the book until it stops.

This phenomenon can be observed in everyday scenarios such as cars decelerating when brakes are applied; the friction between the tires and the road surface is what enables the car to come to a halt. In essence, friction converts kinetic energy into thermal energy, resulting in a decrease in the motion of the object. Therefore, it is accurate to say that friction opposes the motion of objects and can effectively cause them to slow down or stop entirely.