Answer:
According to newton's first law of motion, friction is required to make an object slow down.
Step-by-step explanation:
According to the Newton's first law of motion, for an object to change its velocity (either a change in the magnitude or the direction), there must be a cause to it which is defined as a net external force.
For example, an object which is sliding across a table or floor slows down due to the net force of friction that is acting on that object.