Final answer:
The need to let up slightly on the brake pedal as you come to a stop can be explained by the relationship between static and kinetic friction.
Step-by-step explanation:
In terms of the relationship between static and kinetic friction, the need to let up slightly on the brake pedal as you come to a stop can be explained as follows:
When you first apply the brakes, static friction between the brake pads and rotors prevents the wheels from rotating, causing the car to slow down. As the car slows down, the static friction transforms into kinetic friction, which is the friction between the tires and the road. The stopping distance increases when the brakes are applied suddenly because the initial static friction provides a larger braking force to stop the car instantly, whereas with gradual braking, the static friction gradually transitions into kinetic friction, resulting in a smoother stop.