Final answer:
A curb underneath a tire usually refers to the role of tire friction in handling curves at high speeds. At tollbooth stations, a wire touching the car likely signals an approaching vehicle. Understanding tire conditions and vehicle dynamics is essential for safe driving.
Step-by-step explanation:
When a person driving in a car has a curb underneath the tire, it's likely due to tire friction. This friction is crucial for handling curves at higher speeds, especially on steeply banked and sharp curves. For instance, at a speed of about 165 km/h, tire friction is what allows the vehicle to maintain traction and safely navigate the curve without skidding off the road. Similarly, the contact wire at tollbooth stations serves a practical purpose. The wire is usually there to trigger a system that says a vehicle is approaching, which might be used for counting vehicles, activating signals or for automatic toll collection systems.
In a broader context, the reference to tire pressure increasing with temperature and flexing during driving illustrates the important relationship between tire conditions and vehicle safety. Vehicle dynamics, such as the angular velocity of the wheels, play a significant role in determining the linear velocity and overall control of the car.