Air fills an automobile tire at a certain pressure that is greater than atmospheric pressure. As explained by the kinetic theory, what causes this pressure?

Answer: billions of gas particles colliding with the inner walls of the tire.

Explanation:

The kinetic theory assumes that gas particles are simultaneously colliding with one another and with the walls of their container, in this case the inner walls of a tire. The force of these collisions per unit of the walk is measured as gas pressure.