Question

An inflated car tyre is considered to have a constant volume, regardless of any changes in temperature

or pressure. Use the kinetic theory of gases to answer following.


a) How does the air in the tyre exert pressure on the walls of the tyre?


b) Why is the pressure the same at all points on the inside wall of a tyre?


c) What happens to the pressure on the inside walls of the tyre if the temperature of the air increases? Explain your answer.


d) More air is pumped into the tyre whilst the temperature is kept constant until there are twice as many molecules as before. Explain why you would expect the pressure to be doubled

Answer 1

The air in the tire exerts pressure on the walls of the tire due to the collisions of air molecules with the walls. The pressure is the same at all points on the inside wall of a tire because the air molecules are evenly distributed and in constant motion. If the temperature of the air inside the tire increases, the pressure on the inside walls of the tire will also increase.

Step-by-step explanation:

a) How does the air in the tyre exert pressure on the walls of the tyre?

The air in the tire exerts pressure on the walls of the tire due to the collisions of air molecules with the walls. According to the kinetic theory of gases, gas molecules are constantly in motion and colliding with each other and with the walls of their container. These collisions exert a force on the walls, resulting in pressure.

b) Why is the pressure the same at all points on the inside wall of a tyre?

The pressure is the same at all points on the inside wall of a tire because the air molecules are evenly distributed and in constant motion. This means that the number of collisions with the wall per unit area is the same everywhere, resulting in a uniform pressure.

c) What happens to the pressure on the inside walls of the tyre if the temperature of the air increases? Explain your answer.

If the temperature of the air inside the tire increases, the pressure on the inside walls of the tire will also increase. This is because an increase in temperature causes the air molecules to move faster and collide with the walls more frequently, exerting a greater force and increasing the pressure.

d) More air is pumped into the tire whilst the temperature is kept constant until there are twice as many molecules as before. Explain why you would expect the pressure to be doubled.

If more air is pumped into the tire while the temperature is kept constant, the number of air molecules inside the tire will increase. According to the ideal gas law, pressure is directly proportional to the number of gas molecules. Therefore, if the number of molecules is doubled, the pressure will also double.

Answer 2

The air in the tire exerts pressure on the walls due to the motion of gas molecules. The pressure is the same at all points on the inside wall because of the uniform distribution of molecular collisions. The increase in temperature leads to more energetic collisions, increasing pressure on the inside walls. When the number of molecules doubles while keeping the temperature constant, the pressure doubles.

Step-by-step explanation:

(a) The air in the tyre exerts pressure on the walls of the tyre due to the random motion of the gas molecules. As the molecules collide with the walls, they exert a force which results in pressure.

(b) The pressure is the same at all points on the inside wall of a tyre because the gas molecules are in constant motion and collide with the walls uniformly. This results in an even distribution of pressure.

(c) If the temperature of the air inside the tyre increases, the kinetic energy of the gas molecules also increases. This leads to more frequent and energetic collisions with the walls, increasing the pressure on the inside walls of the tyre.

(d) When more air is pumped into the tyre while keeping the temperature constant, the number of gas molecules inside the tyre doubles. Since pressure is directly proportional to the number of molecules in a given volume, doubling the number of molecules would result in a doubling of pressure.