How does friction operate in a car when the brakes are applied?

When brakes are applied in a car, the brake pads come into contact with the brake discs (or rotors). This contact generates friction, which is a force that opposes the motion of the wheels. The friction created between the pads and the disc converts the kinetic energy of the moving car into thermal energy (heat), slowing the car down effectively.

This process is crucial in the operation of braking systems. The greater the pressure applied to the brake pads, the more friction is generated, leading to a stronger braking force and a quicker reduction in speed. Hence, the correct answer highlights this fundamental principle of how brakes function, emphasizing the role of friction in creating the necessary resistance to stop the vehicle.