Question 6: Why does the pressure of the air in automobile tire increases if the automobile is driven for a while?
We know that when an automobile is running on the road, there is friction between the road and its tires. In fact, the tires of the vehicle overcome the force of friction offered by the surface of the road and the vehicle moves onward. The work done against the force of friction appears as heating up the tires. The heat is then transferred to the air molecules contained into the tire which increases the kinetic energy of the air molecules and they move faster and faster. The more speedily moving molecules have now a high rate of collisions with the containing walls of the tires. The increased rate of collision increases the pressure on the walls of the tire and hence the pressure of the air in the tires of the automobile increases.