Question

The air pressure in a car tyre may increase considerably on driving the car some distance at high speed. This is due to (1) Triction (2) Frictional heat on tyre leading to cxpansion of air inside the tyre (3) Lcakage of air from the tyre (4) Effect of changing atmosphcric pressure

Short answer

Option 2: Frictional heat on the tire leading to expansion of air inside the tire.

Step-by-step solution

- Analyze the Given Options

Review each option carefully to understand the possible reasons for the increase in air pressure within a car tire.

- Evaluate Option 1: Triction

There seems to be a typo in 'Triction,' which is likely meant to be 'Traction.' Traction refers to the grip the tire has on the road but doesn't directly cause an increase in air pressure within the tire.

- Evaluate Option 2: Frictional Heat Leading to Expansion

When driving at high speed, friction between the tire and the road generates heat. This heat can cause the air inside the tire to expand, leading to an increase in pressure.

- Evaluate Option 3: Leakage of Air from the Tire

Leakage of air from the tire would decrease the air pressure inside the tire, not increase it. Therefore, this option is not correct.

- Evaluate Option 4: Effect of Changing Atmospheric Pressure

Changes in atmospheric pressure are generally too small to significantly affect the air pressure inside a tire during a typical drive.

- Choose the Correct Option

After evaluating all the options, it is clear that frictional heat leading to the expansion of air inside the tire is the most likely reason for the increase in air pressure.

Key concepts

frictional heat

When your car's tires make contact with the road, friction occurs. The frictional force is necessary for your car to move and stop effectively. However, this friction generates heat.
Frictional heat is a common phenomenon encountered during high speed driving. When the tires rub against the asphalt, the kinetic energy from your car's speed converts into thermal energy. The faster you drive, the more heat is produced.
This heat transfers to the air inside the tire. The walls of the tires warm up and so does the air within them. This increase in temperature affects the air molecules, causing them to move more rapidly, which we'll explain further in the next section.

air expansion

As frictional heat warms the air inside the tire, it causes the air molecules to move more vigorously. According to the principles of physics, increased thermal energy in a gas leads to increased pressure if the volume of the gas remains constant.
The increased movement of the air molecules results in expansion. Air expansion in tires is a direct consequence of increased internal temperature. The air inside the tire exerts a higher pressure against the inner walls of the tire.
This is why you may notice that the tire pressure is higher after driving for a while, particularly at high speeds. It’s a natural response of air molecules to the added heat energy from friction with the road.

high speed driving

Driving at high speeds significantly influences tire air pressure. The primary reason is that high speeds amplify friction between the tires and the road surface. This leads to a more substantial heat generation.
The heat generated from friction is absorbed by the tire and the air inside it. When cars are driven fast, the tire needs to cope with these increased temperatures more efficiently. Regular checks and adequate maintenance of tire pressure are crucial, especially if you frequently drive at high speeds.
High speed driving also increases the chances of tire wear and tear, which can lead to other issues like blowouts if tire pressure isn't managed correctly. Always ensure your tires are within the manufacturer-recommended pressure range before embarking on high-speed drives.