Test and analysis: (1) If the bicycle is taken as the reference, the bicycle is in the west of the car, and the distance from the car is getting farther and farther, so the cyclist is moving westward.
(2) In order to reduce the vehicle speed, tighten the brakes, increase the pressure of the brakes on the wheels and increase the friction. Because there is friction between the brake pad and the wheel, the wheel should overcome the friction to do work and increase the internal energy of the brake pad by doing work.
(3) Bicycles made of carbon fiber materials are about the same size as ordinary bicycles, but their mass is smaller than ordinary bicycles, indicating that the density of carbon fiber materials is small.